I heard from a friend that there are agencies that provide bareback after testing, does anyone here know about such agencies?
I am not recommending this, as I myself have not done that, chickening out in the last minute

Just answering your question
There are a few Bareback parties in Germany they tested all visitors on site before the party began. The guest pay the test.
They hold it in a few cities in Germany a few times a year.
The most renown one is spermagame. I heard people even do CIP.
In Germany BB party is called AO (Ales Ohne) party so if you do search using that wording you might get a better result.
External Link/Members OnlyAlternatively if you are a stud, fit, young and reasonably good looking you contact the porn producers. You might even get paid to fuck, creampie CIP a good looking young European Pornstar