Entity deleted

I deleted a thing on the Overview dashboard to see where doing that has effect.
The same thing on my user dashboard also turned into ! Entity not found.
Trying to edit my user dashboard and [ + ] a card in the right section, search entities, it would seem that I’ve lost that entity from the list, not just the Overview duplicate output display indicator of it.
That entity must be arriving because it is from a smart plug. I can work out what that missing entity should be named from the other entities from the same smart plug.

How do I get it back ?

You add it again ( depends upon how/and where you deleted it )

lots of tries to do that didn’t work and mouse-poking other Entities on the same Device ended up breaking them too. Deleting the Device from its System > Devices & services > Integrations > brandname > device … menu to the right, then (+add device), removed and then returned to the same device state with Current disabled. The device itself was fine; I could find a number in its diagnostics page near line 500 containing the correct integer milliAmps current, but the home assistant Entity representing it was disabled and refusing to fix after “The enabled entities will be added to Home Assistant in 30 seconds (ok)
(Update)”

and some device delete later from Settings > Devices & Services > Integrations > brand name > device … Delete

What did work, only when logged in to home assistant as the owner/administrator user, was to do System > Backups
click on a drive logo right of a backup state
“restore”.

The red text “restore” was available to owner-administor and not visible to a lesser administrator-user. That is, you can ignore instructions online which start “at the Supervisor tab on the left”. If you are just a user or an administrator-user, then log out and get your owner-administrator user to log in with their admin password to restore from a backup.

LOL … well atleast i now know that you can read , your next step would be to not “Poke Around” with things you don’t understand, on the other hand, some people like to learn by “trial and error”