I accidentally deleted a user account from Windows 11 and I am now working on the administrator account. Is there a way to recover the deleted account?

can you hold down Win+R keys, type in netplwiz and press enter. See if that user account is listed? If not, click on Add, log back in, that should create the account again. You can then double click on that account, go to group membership tab, make it administrator if needs to be.