League top scorer event

[madflo19]

I have a question about the top scorer event as 3 days now Support is telling me that it doesn't matter if i didn't joined the event(at the event screen) at any time of the season,but most probably someone beat me "the last minutes of the season" and that's why i don't have the claim button(that's impossible as i had the last game many hours after all the other fixtures of my league and after this last game my player and one opponent playere had 29 goals each.
So if any of the admins will be kind to enlighten us about if it is mandatory or not to press the "join the event" button at any point of the season, i will appreciate .
Thanks in advance.