Open the YouTube app or YouTube Studio
Sign in to your account
Tap the Create button
Select Upload a video
Choose a vertical video under 60 seconds
Make sure the video is in a 9:16 aspect ratio
Add a title
Include #Shorts in the title or description if needed
Select a thumbnail if available
Choose the audience setting
Add any other details you want
Tap Next
Review the upload settings
Tap Upload or Publish