This page of the FUT 22 mode guide to FIFA 22 will tell you when you can claim your FUT Champions rewards.
The FUT Champions is a prestigious weekend league in FIFA Ultimate Team mode, in which only the best players can participate. The competition isn't open to everyone, as you first have to qualify for it by earning enough FUT Champions points, which are earned through playing matches in the Division Rivals.
In the FUT Champions weekend league in FIFA 22, you can play a maximum of 20 matches and depending on how many points you manage to score, you can obtain specific rewards - you get 4 points for every win and only 1 for each loss. The weekend league rewards in FIFA 22 Ultimate Team can be claimed immediately after playing all the matches, by logging into FIFA 22, into the web app or the FIFA Companion mobile app.