Santander - Principal Only Payments

I can't seem to get a straight answer from anyone at tesla, and the people at santander are clueless. They won't talk to me without an account and I don't have an account yet because I haven't picked up the car.

I financed 15k with them through tesla financing. Luck of the draw and I was assigned santander.... yay...

Two months from now I want to pay off everything as a principal only payment so I can avoid about 4,500 in interest.

Has anyone had experience with Santander? Do they allow principal only payments or early payoffs so I can avoid paying all that interest?

Example - total amount financed 15k.

Total cost of loan over the duration of the loan terms is about 19,500.

I want to pay them 15,000 and just pay the dang thing off to avoid the additional 4,500 in interest.

Is this possible with Santander, or do I need to scramble to get my own financing with my local bank?

I have scoured google and searched this sub, along with the model3 sub looking for any kind of similar post. I cannot find anything except people griping about how terrible Santander is. lol