Go to your immigration office and get a copy of the list or required documents. If you did it last year , I’m sure it will be the same as the previous year. Check with your immigration office I know some differ about when you can apply
If his non o visa is based on marriage than he can get a work permit. If it is a retirement visa than he is not allowed to work . He would have to change his visa
Did they come and do a house visit ? I am going to do mine and they said this year no Thai witness they will come to my condo for a visit. Jomtien office