I cant really remember how I used to do them, I think turning abit as you’re taking off helped. Definitely easier over a spine/volcano type jump. 90 degrees is definitely possible on the right jump, would fancy doing one over a jump with loads of length though, big chance of coking it up.
No idea what video you mean, but turn to one side on the take off and push the back end out through your hips, turn back into it to straighten out, push down and land front wheel first, scrubs are a very similar movement but dip your shoulder more. Timing matters too . now go practice!