I think you can get information from Catholic Relief Services, (CRS)
crs.org, also try Maryknoll
www.maryknoll.org . and Maryknoll Lay Missioners:
mklaymissioners.org/. Also worthy, Jesuit volunteers
jesuitvolunteers.org/
Try googling the words Catholic Missionary and see what comes up, you’ll be surprised at all the options. Good luck!