Marry foreigner and migrate over

Any single mom marry to foreign then stay abroad with your husb? How you make arrangements for the child? I have a sole custody. Do I still need to tell my ex husb that I bringing the child ? My ex husb was given a visitation to visit the child. Till the separation and divource over till today he hasn't come and visit the child. The only thing he do is give monthly maintenance. What if my ex hus say you cannot take the child away? My child is 5 yrs old. He left me and my child when he was 1 year plus. How to go about. I m confused.