retracting a move

my opponent sent me a message that he would like to "take back" his last move - i don't have a problem with that - how can that be accomplished?

@coneykid said
my opponent sent me a message that he would like to "take back" his last move - i don't have a problem with that - how can that be accomplished?

It can't you can start a new game with the starting set-up of the position you just left.

https://www.redhotpawn.com/chess/chess-fen-viewer.php

@coneykid said
my opponent sent me a message that he would like to "take back" his last move - i don't have a problem with that - how can that be accomplished?

It can't and if Russ allowed it via feedback I expect he would be snowed under with requests so it's not going to happen.
What you could do is agree a draw in the game and start a new one replicating all the moves until the take back one