Which step are you referring to, @RachelL?

Normally, if you are using bills for vendor expenses or projects, KhimG's answer is the best resort to record a credit. You may follow the steps outlined from her previous post.

Also, this article list all the process for you: Enter a refund from a vendor.

If you're pertaining to MorganB's recommendation to write a check, this process will only work if you want to record a refund towards a customer. Checks are expense transactions which reduces the bank balance.

On the other hand, a credit from a supplier means a return of funds. Therefore, we need a vendor credit to put back the money in the register and offset the Accounts Payable balance.

Let me know how things go or if you need further help with this topic. I'll be right here to help you anytime. Have a good week ahead!