Users ldap and DB

hello
i have setup new instance on nextcloud (v 22.2.3 ) … i enable ldap intergration and synchronize users from our AD. now i need to add some “externa” users … when i try to add new user and send form … i have an error “Bad request”
in logs i see that nextcloud trying to create user in my ldap … (but i don want to have this account in my LDAP.) so question is
how to make interdnal DB and LDAP integration …