In v11 & 12 it's under the standard Motion Effect available for every clip.
Insanity is hereditary, you get it from your children
If this post or another user's post resolves the original issue, please mark the posts as correct and/or helpful accordingly. This helps other users with similar trouble get answers to their questions quicker. Thanks.
A quick way would be to right click the clip on the Timeline and then select Rotate 90 Left or Rotate 90 Right.
This same cell phone video orientation matter was mentioned only yesterday in another thread
Please refer to graphics in post 41 in the reference that I have cited.
You might consider recording your cell phone video holding the phone in the alternative orientation to avoid this
type of finding in the video editor.
We will be watching for your progress.