moving to a different state after divorce

I am recently divorced and have decided to relocate to a different state. I currently live in Hawaii and my desired state of residence is Oregon. I am looking to move within the next month and am looking for assistance to make a simple legal consent for my ex-husband to sign. He wants this move approval in writing, even though he's verbally approved this, and also sent emails/texts to that effect. I am looking for reliable and experienced professionals that can help with the very simple wording that this should require. He insists this be legally sound.