There is more info in the answer to this question: General questions about XP calibration
Basically you just need a ton of people to play your map so the system can figure out an appropriate XP award based on various averages. That’s “calibration”. This is necessary because the accolade devices don’t award a specific amount of XP, but rather a variable amount based on many factors.
(None of my maps have ever had enough plays to be calibrated, which means they don’t award XP despite having accolade devices.)