-Do everything normally up until 22B > 22BC~66 > 6C (the computer doesn't dash cancel in the sample, but it makes it easier to connect the 6C and is also a good habit to get into for her other combos)
-Delay the OpticA and the following 66C for as long as possible; you want to be delaying the OpticA for quite a while, but the 66C not so much. This is to make the next part (j.D > 6D) easier to land.
-Super jump cancel your j.D to make it easier to connect the d.6D. Landing a j.D at the highest point in your jump is usually the best way to go about using the j.D > ender combo. You'll cross up when you sjc, so make sure you adjust your combo accordingly.
I hope that helps you get it down, but honestly I would be using
this version of the combo (as well as the other optimised challenge combos found in that video) instead.