Remove it and take it to your local belt/bearing supplier? They would fix you up with a suitable replacement. Difficult to make any actual suggestions without knowing your location.
Do note where the belt adjustment is at, currently. The replacement size may need to be one size different, dependent on that.
Edited to add that I use ABC in Peterborough.
Edited By not done it yet on 29/03/2022 13:20:22