I can’t afford to pay the vet bill outright which is why I have insurance. Pet Plan says they will do direct pay all they need is a Pre-Authorization form from the vet which list the procedures and the cost. But my vet does not want to give them an estimate in case its more than they estimated.

Our software has a high and low end estimate. See if you can convince him to give a pretty high end one. I’m sure he’s been burned by a pet insurance company before.
I’d much rather deal with the care credit folks than pet insurance companies.