drywall corner bead
The spray is for plastic trims. The type of bead you have is put on with joint compound. The plastic trims are full of holes that allow compound to push through and help adhere the trim to the board. The adhesive is to hold it in place until mudded. The joint compound holds long term.
Apply a layer of mud to both sides of the corner. Firmly push the bead into place and wipe the excess from the sides. Allow to dry and a couple of finish coats.........you're done.
If you can read this, thank a teacher. If you can read this in English, thank a soldier. Support our troops.