Will for funds while seasoning

[Diana Acorn]

HI there everyone,

My brother is "gifting" me $100k for a down payment to purchase a property where we will share ownership. (I'm applying for the loan without him). He wants me to create a will that ensures that if something happens to me while it's held in my account for seasoning, he'll get his money back.  (Full disclosure: I don't currently have a will).  I tried to use the DIY templates found in my legal insurance plan but they only allow you to enter perecentages, not dollar amounts.  Any tips on how to create a document indicating that the $100k goes back to him in the event of my demise?