Hi,
you need to intercept Loc first , the system'll not track the Glide without Loc.
Then you need to write an altitude higher than the one you'll intercept the Glide ( because if you arrive on glide capture zone with ALT* displayed the system 'll complete first the capture of altitude , so you'll miss the Glide)
then set a V/S as per your SOP regarding altitude and.....remember to push
APP because you are tracking the loc in Loc.