Explosive / Instant Popup - Learning Tips

Im 46yo and im struggling to learn instant popup. Im reasonably fit and 71kg and really not sure what my issue is. i found this this video best so far
yet i cant flick my legs and lift my body. I always seem to use my toes. has anyone found this popup technique hard to master? I would be grateful for any tips, progression steps, sharing their learning curve etc thanks
yet i cant flick my legs and lift my body. I always seem to use my toes. has anyone found this popup technique hard to master? I would be grateful for any tips, progression steps, sharing their learning curve etc thanks