open gallery>click 3 dots at top right corner>select recycle bin
if you are having active Google account and proper backup..then try Google photos
check your backup account..
Dear Samsung Member,
Greetings from Samsung Customer Support!
We would like to inform that if you have taken Data Backup with Google and Samsung cloud, only then you can retrieve your data by following these steps: Apps > Settings > Accounts and backup > Samsung Cloud > Back up this phone > Back up > Tap OK on the pop up > Done.
For further assistance, register your concern in Samsung Members Application (Open Samsung Members Application > click on “+“icon > send feedback > error report/ask questions).
Thank you for writing to Samsung.
Samsung Customer Support