Thats usually a sign, you need knew clutch fibers or try adjusting the clutch.
To adjust the clutch.
you have to remove the right side cover. this means removing the gear shifter and the right side foot ped to be able to pull the cover off.
in the center of the clutch, you will see a small nut and a flat head in the middle of the screw. you have to loosen the nut and turn in to adjust and then re-tighten.
This may help, but you likely need new fibers. around $30 dollars give or take.
Do you know when the last time they were changed if ever ? what year you have ?
Sometimes, you can also try adjusting the clutch cable.
Also check your oil level and when is the last time you changed the oil ?
Sporty