Tummy time in a harness

Hi all, how do you do tummy time with your little ones when they they are in the harness. I’m conscience I’m not doing it but don’t want to hurt her

We were told do as much as poss as it’s a great position For the hips ! my little one was in it from 12 to 18 weeks x

When my baby was in a pavlik harness (5 weeks old - 12 weeks) we rolled up a towel and put it under her which was recommended by the consultant x