Whenever you have an FTP increase, that info should be saved in the ride history/activity. Usually when that pops up on the screen you’re a little cross eyed & breathing very hard….it’s hard to get a screenshot.
It is saved somewhere, but not sure exactly where… Take a look in your in-game profile; I think(?) it will autopopulate there. Don’t look in your zwift[dot]com profile as that ftp value is different.
Dont the new auto screenshots capture it now?