Blender needs to know what channel you want to keyframe. Select the transform strip, press N to show its properties and either press I or RMB / Insert Keyframe with your mouse curser over whatever strip property you want to animate. This will add a keyframe for that channel. Repeat as neccessary.
This is the same way you keyframe anything in blender
IT?S HARD TO LOOKING FOOOORRRR!!! THANNNKKK YOOOOUUU
FINNNNNAAALLLLYYY RESOOOLLLVEEEDD THANK YOU MILLION!!!
but guide online ufficial of blender hasn’t this information details…
BUT THANK YOU!!