My question involves a child custody case from the State of: Maryland

My children's father is currently incarcerated (rape, assault, sexual offense), only one child has his name on the birth certificate.

I have sole custody of our three children, without right to visitation "until further order of court" for their father.

I want to find out what steps I need to take in order to get a passport for my children so we can visit our family in Canada. Do I still need his "permission" to get a passport even though he is incarcerated and I have sole physical and legal custody from courts of MD?

Thank you!