Nextcloud AD/LDAP couldn't run successful

Hi
I am beginner in Linux, I have installed nextcloud 20 on ubuntu 18 server using apache2, while I trying to connect to the AD using steps on nextcloud docs, the LDAP app can detect the port but couldn’t detect base DN, even when I type the base DN manually the test gives an error.
any Idea about this situation ?
the srerver
ldap://10.100.250.30
the credential
cn=admin,dc=mydc,dc=local

  • the base DN*
    dc=mydc,dc=local
    when I am testing the base DN the notifications appear
    The Base DN appears to be wrong
    :heavy_multiplication_x:LDAP Operations error

also at logging section I have these logs
Error PHP Error: ldap_search(): Search: Operations error at /var/www/html/apps/user_ldap/lib/LDAP.php#341
Warning user_ldap Bind failed: 49: Invalid credentials
Warning user_ldap Configuration Error (prefix s01): login filter does not contain %uid place holder.
Warning user_ldap Configuration Error (prefix s01): No LDAP Login Filter given!
Warning user_ldap Configuration Error (prefix s01): login filter does not contain %uid place holder.
Warning user_ldap Configuration Error (prefix s01): No LDAP Login Filter given!