Looking good! I would actually lower to bottom hand a tinny bit more, AND you need to bring the upper body and lower body closer together into a tuck, this will allow the bottom leg to take on more weight making the flip easier.

Look at minute 2:30 https://www.studioveena.com/tutorial/superman-1075/ Pause it an you’ll the slight difference between our entries. Look at how close I bring my legs to my torso.