For a more challenging warm-up, you can try below series with breathing cues:
Begin with Ardha Padmasana ("Half Lotus Pose") by placing your left heel on top of your right hip crease and resting your right knee on top of your left foot or Padmasana ("Lotus Pose") by placing your left heel on top of your right hip crease and placing your right heel on your left hip crease.
Place both palms on the mat next to your hips, spread your fingers slightly for stability
(Inhale) Engage your core and lift off the mat by drawing your navel towards your spine and leaning forward slightly
(Exhale) Release and lower back down onto the mat
While in Ardha Padmasana or Padmasana, keep your feet relaxed and allow your soles to face upwards.
What if you find it difficult to lift off from the mat? Firstly, you can consider placing your palms onto Yoga Blocks instead of placing them on the mat. Secondly, if you are in Ardha Padmasana, you can ground one foot onto the mat for support and then try to lift off from the mat. If you are in Padmasana, try to work on engaging your core muscles and lifting off from the mat in Ardha Padmasana.