Pixelmon Mod

Why can't the crystal server be able to use Tm? Or does Move Tutor not work?

We're not associated with any specific server, you're probably better off asking them.

TM issues may just be due to the fact that we updated all move sets to their latest available stat sets (as of the Sword/Shield expansion Isle of Armor). Pokémon with move sets in Gen8 need the Galarian TMs or TRs.