How to reach a climax

Ladies I need help and advice. I’m 28 and have never had an orgasm from penetration. Only from oral but I desperately want to know how. My partner knows and is ok with it but I just find it frustrating the only way I reach a climax is is when he is down there. During penetration it feels amazing and I can just imagine the feeling of reaching one while doing it that way. I’m starting to think it’s clitoris stimulation that gets me there? Ugh please help!