Exposing services

Hi everyone!

Since the announcement of the Raspberry Pi 5 I have started going down in this path of self hosting. Mainly for fun/convenience, but also to learn a bit more of docker, networking etc.

So, forward some weeks I got my RPi5, I am running some services, got Nginx Proxy Manager and Pi-hole to let me use names instead of ip:port and decide it was finally time to try and expose it to the internet. I bough myself a domain at cloudflare, followed some tutorials about opening ports but nothing worked.
After some thoughts and debugging I realized this issue is because of the network settings in my apartment:

My Raspberry is connected to a Tp-Link router (Router 2) through WIFI and this router is connected to the ISP router (Router 1), an CH7465VF from Vodafone through Ethernet.

   (--------)       +----------+       +----------+        +--------+
  ( external )------| Router 1 |-------| Router 2 |--------| Server |
   (  world )       +----------+       +----------+        +--------+
     (-----)

I had only configured Router 2, I also have to forward Router 1, right? It turns out that the Router 1 does not have this option. The only thing that would resemble this, by name at least, is IP and Port filtering. But this does not seem to solve anything as well. Contacting the ISP is not a good solution as well, the under the contract is of my landlord and he lives abroad/the management company is not the friendliest.
I am looking for pretty much any (preferable free) solution or advice for this situation. I don't really need for the most private solutions (I tried cloudflare tunnel, but I did not understand how to set it correctly to expose all my services) .

Thanks for your time!