Check the Google Photos app
Open the Library or Trash/Bin folder
Restore the deleted video if it is still there
Check the Gallery app Trash/Recently Deleted folder
Check your file manager’s Recycle Bin or Trash
Restore from an SD card backup if the video was stored there
Check Google Drive or other cloud backup apps
Restore from a local device backup if available
Use a data recovery app from the Play Store
Connect the phone to a computer and use recovery software
Stop using the phone immediately to avoid overwriting the deleted video
Contact the phone manufacturer or a professional data recovery service if needed