as has been mentioned before, your best bet would be a two pronged attack
Open up the hip flexors , for this i’d recommend bulgarian split squats (no extra weight needed) and just go as deep as you can accumulate a few seconds drive up and repeat, try and set it up so you can constantly go deeper. I.e. have your knee touch a pad, next week try and have your knee touch a lower pad and the week after try and get to the floor.
Next KB swings, drive your hips forward hard and make sure you focus on externally rotating your femur. In simple terms twist your thighs outward.