Upper Lip Scar following Mohs Surgery
It appears to me that the lip to your right side of the scar is thicker than the skin to the left of the scar. There is also a slight "step off" where the 2 sides meet.
The Mohs surgeon was forced to attach 2 sides of unequal bulk together. He/she did a good job. The slight irregularity could be improved with minor surgery under local anesthesia.
CO2 laser could significantly camouflage the vertical scar. Then, a variety of fillers or a Permalip Implant could give you the fullness you want.
In general, lip volume can be nicely improved with a hyaluronic acid filler like Juvederm or Restylane; these are temporary solutions, but typically have predictable results. More permanent options include medical grade silicone injections, fat grafting, and lip implants; these typically require lots of experience, and are less frequently done. Your photos also suggest some raised and possibly firm scar tissue on the "less favorable" side of the lip. Steroid injections can go a long way towards softening and flattening this, if present. I think you would do well to consult with a dermatologist or plastic surgeon who performs lots of cosmetic injections, and discuss your options with him/ her. Good luck!