It’s a base64 encoded URL. You can usually recognize base64 by the two equals signs at the end. Just do a google search for a base64 decoder, and paste that text into it. You’ll get a usable link. (Technically you can decode them directly on your computer, but I don’t feel like walking you through the console commands for that…)
The base64 encoding is mostly to prevent bots from automatically issuing takedowns on piracy-related discussions. Because there’s the plausible deniability of “well we weren’t posting links.”