MegF.
That's for sale???
Abcesses in reptiles are usually solid, not liquid filled. That looks far more serious than that. If you can't get it to a vet for treatment, i.e. sensitivity testing for which antibiotic will work on it, than I suggest euthanasia to keep the animal from suffering further. That looks like something that has been going on for a while. How long has it been like that?