EIN for Irrevovable Trust

My dad died in March 2022. He had an revocable trust account at his brokerage company and I was the trustee. Upon his death, I obtained an EIN and the revocable trust was converted to an irrevocable trust. I then sold all the assets. I closed the irrevocable trust account several months after I sold the assets and I'll pay the taxes due on the capital gains (after the step-up). If he receives any checks in the future, how can I cash the check(s)? Do I have to open a checking account using his EIN and deposit the check? How would I then cash the check? Thank you.