Newbie need help Land Trust

I’m getting ready to purchase a home sub2 and put it into a land trust. How am I able to write off the mortgage interest if the mortgage isn’t in my name. is there a form I need to fill out or something in order to write it off on my taxes?

Who are the settlor, trustee, and beneficiary?

I have no clue. It’s my mother-in-law’s home. I’m purchasing it from her. I’m having an attorney do the trust.