Sorry to hear about the scar! It must have been a traumatic experience.
For most optimal results, I would advise a combination of subcision + filler/Rejuran & resurfacing laser.
Whether an atrophic scar would benefit from subcision + filler/Rejuran would depend entirely on clinical examination.
If suitable, my recommendation would be subcision and Rejuran instead of filler for your scar over the glabella area. It is important to note that there are blood vessels from the eyes that supply this area which if compressed/blocked by fillers can lead to blindness.