My laptop came with Office pre-installed but I have this banner showing up every time I open it, is there a way to disable it for good?

Uninstall it and go for OnlyOffice (interface etc pretty much like MS Office) or if you are a bit more experienced, go for LibreOffice.

LibreOffice has a bit of a learning curve, if you come from MS-Office but I think it's very much worth it.
- A highly underrated feature of LibreOffice Draw is the ability to edit PDFs. Sure it might mess up a font here or there, but there's no way in hell I'm going to pay adobe an absurd amount of money for that one feature.
- Ms office has a bit of a learning curve if you come from libreoffice, especially learning to forget the PowerPoint doesn't support styles
~~Hasn't only office had like one update in the last 10 years or something? I stopped recommending that years ago.~~
Edit: not only office, open office doesn't get updated. I misread and mistyped.
- Are you thinking of OpenOffice, maybe? OnlyOffice's latest stable release is only three weeks ago, while OpenOffice has only had incremental updates to version 4.1 since 2014.
- During the last 13 months, they have pushed out 9 major updates.
only office it's the way to go

Looks like whoever you bought your laptop from installed a pirated or non registered legit copy. Short of buying a real license, there is no legal way to get rid of the banner that I am aware of.

I believe it’s common practice for Windows laptops to come preinstalled with Office 365 now. I don’t think it’s pirated. It’s just not licensed like you said.
OP, I’d recommend just using LibreOffice. It works fine for most situations.
- You're correct that it often comes pre-installed, but the banner on those say "Office has not been activated" not "The license isn't genuine"
I bought it from a legit store though, it's not second-hand or something
- The Office that comes pre-installed is often just a trial, and you need to buy a license or a Microsoft 365 subscription to use it. LibreOffice is a good free alternative, if you don't specifically need the Microsoft applications, and it will read and write MS Office files.
- You’ll need to take it back in to the store and show a manager.
- do you have a receipt? does the receipt show that it includes office? if it does, take it back to the store.

do not trust laptop sellers. even if it is brand new just erase it and install os yourself. 5 year old can do it.

Where the fuck did you get your laptop...

My 2nd hand laptop seller had the decency to crack the preloaded software before selling it to me. His remote access tool wasn't too resource-intense either.
- Was he frugal with how he spent your bank funds, Steam wallet, and crypto?
- And the botnet software only uses 5% CPU so I don't even notice

A quick search seems to indicate that this is "normal" even on legit Office installations. You can check out the link below or go through these steps that the site suggests to see if it helps:

https://www.minitool.com/news/remove-get-genuine-office.html

Remove Get Genuine Office by Disabling Connected Experience in Office

Open any one of Office Product, Word, Excel, PowerPoint, etc.
Click File on the top left and select Options at the end of the left menu.
A new windows will pop up. In the default General tab, find and click the Privacy Settings button.
In the Privacy Settings window, scroll down to find Enable connected experience and uncheck it.
Click OK to save changes.

(In Outlook 2016 and later, you should navigate to File > Office Account > Account Privacy > Manage Settings. Turn off this connected experience option will disable experiences that analyze your content, download online content, as well as other connected experiences like co-authoring and online file storage.)

They said that didn't work

No computer, on EARTH comes with licensed, paid for MS Office installed. Period.

They now ship the "apps" installed, but that doesn't mean you own them. You no longer EVER own them. You subscribe and pay. Period.

If you want to use those trash applications, subscribe and pay them. If you want to not, Install LibreOffice.

How bad do you need office? Uninstall it then grab the free version which is effectively a web app.

Legally, you can either uninstall Office or buy a license for it.

What I would do is go to this website and follow the instructions

the bless of being in a non-company-owned plataform, is that this isn't going to be deleted
I had the same problem as OP, used MAS and it worked, the notice was gone

You can get legit 2021 office licenses cheap, I used gamers-outlet.net

I don't need all the cloud stuff, just need to open word docs sometimes. I think I paid $9 for office and $8 for server 2022.

They are not really legit... It's people selling developer key from MSDN.
Beware that some of them are not legit at all. They often are parts of volume licenses, which, theoretical, are linked to one company. Because of that they mostly are single use and cannot be used to activate office a second time.
- Ah. I only use it for home anyway.

Pay Microsoft a subscription fee or use libreOffice or another free and open source tool instead.

If you're an invested user of Office, just get the Microsoft 365 suite. It's a decent value. If you aren't that picky, online office is pretty decent too. And of course there's always LibreOffice.

If I'm doing online anything, I'm doing Google docs and sheets.

You gotta pay the troll toll, if you want to get in to that boys soul.

double check but it looks like a “trial” version office.

trial? there are no pop-ups or notifications saying it's a trial version though
- New computers will often come with a trial of Office 365, installed as "Office Click-to-Run."
I don't think it is a trial version. A trial would not give a warning about being counterfeit. If OP legitimately paid for a laptop with Office, I think they should take it back.