This is apparently missing from Opera (114.0.5282.154 under Linux), and the functionality also doesn't appear in opera://settings/keyboardShortcuts.

Keyboard shortcuts do exist for changing which tab is selected, but not for moving the selected tab along the tab bar. And of course, I don't want to have to fiddle with the mouse just to do this—that's too slow, especially for users with physical coordination issues.

For efficiency and convenience for all users, and basic practicality for some, I urge Opera's developers to add this ASAP.

Thank you for your work.