Amazing!
wow
CAREFUL, SPOILERS:
I highly recommend Cyberchef to do this one. You can use the function "Parse QR-Code" to solve the first step. For step 2 you need to decode it. Try and figure out which format uses an "=" sign to fill up triplets at the end. The last one to me is actually quite hard to find out, if you don't know what to do. But you can see that the position of the ":" and the "_" already kinda makes sense. Maybe the letters just need some rotation?
3 months ago
Interesting challenge took me some time to get the last step.