What should I do to recover deleted contacts from Samsung Galaxy?

WisonLee  If the contacts were deleted recently from your Galaxy phone, you can also use Google's "Undo changes" feature to recover them. To recover deleted contacts from Samsung Galaxy phone with this new feature, go to your Google Contacts on a web browser (contacts.google.com), click on the "Settings" (gear) icon, and select "Undo changes." You can choose to revert your contacts to any point within the last 30 days.

Once you've undone the changes, your contacts will automatically sync back to your Samsung Galaxy device. This method is effective as long as the contact deletion happened within the 30-day window.

P.S. Also go check if there is a local backup on your phone with Smart Switch app. It is Samsung's official tool for device backup and restore.