Ask the board to have a training camp in warm place in the winter break

What team are you, and is this in the first season or second? As there is the World Cup 2022 in December. 

Barcelona, tried 1st season and second season (with the World Cup)

For Barcelona, the option will show under 'club vision - make a board request' on the 18th of December 2021, and the 19th December 2022 for the second season. 

If you have a save file prior to those dates we can double check to make sure it does appear.