Welcome to the forum!
So, the bike doesn't accelerate but it revs up? That's why you think is the clutch? Makes sense to me.
If the bike doesn't accelerate but it doesn't rev up either, then it may be something else.
I would start by the cable having good free play and not getting stuck. Then check the discs. Measure the thickness with a caliper and see if they are beyond service wear. If disc are ok, then check the plates. Last suspicious should be the basket unless you have a reason to believe it's the culprit.
So, the bike doesn't accelerate but it revs up? That's why you think is the clutch? Makes sense to me.
If the bike doesn't accelerate but it doesn't rev up either, then it may be something else.
I would start by the cable having good free play and not getting stuck. Then check the discs. Measure the thickness with a caliper and see if they are beyond service wear. If disc are ok, then check the plates. Last suspicious should be the basket unless you have a reason to believe it's the culprit.