This is the last paragraph taken from the Reward Program FAQ (Link):
Am I required to file a tax form to join the Reward Program?
No. This was previously required from Twitch (under Amazon), however this is not required under Overwolf. Additionally, not tax information or confirmation documents will be supplied by CurseForge or Overwolf.
It seems like they added that paragraph just recently and forgot to color the text - it's black instead of white and therefore almost invisible: