The Buffalo Bills QB says he's down to settle the debate once and for all ... telling the "Good Morning Football" team Wednesday he's formally accepted Mahomes' throw-off challenge!!

"We're working on it," Allen said ... "I'd love to finally settle this and figure it out."

LET'S GOOOO!!!!

If you missed it ... after Allen was given a higher throw power rating in Madden 21 than Mahomes (99 to 97) -- Pat wasn't too happy.

The K.C. Chiefs superstar said he was down to get on a field and prove the video game creators wrong ... telling ESPN he wanted to line up with Allen and see it for real.

"I've yet to see somebody have a stronger arm than me," Mahomes said.

Allen claimed Wednesday the two had a deal in place to get the throw-off done ... but says COVID-19 restrictions have forced them to postpone it.

Unclear when the new date will be ... but Allen says he's hoping the challenge will lead to some charity money.

As for the favorite in the throw-off ... Mahomes says he can throw a ball in the area of 85 yards -- and seems Allen is confident he can match that.