You can adapt what @Alexander_Sosnovskiy came up with in this thread:
I modified the original PG a bit to avoid merge meshes. Also, I set the total number of frames to bake to 500, because the animation is very long: it takes around 1mn to bake it all! You can set numFrames = -1 line 36, if you want to bake them all.
The PG is setup to merge several animations and not a single one which contains different animations. You will either have to update your .glb file to conform to this (and list the animations in the array line 41), or change the way the baking works.