from ldap3 import *
server = Server('myldapserver.com', get_info=ALL)
the_user = 'cn=Manager,dc=domain,dc=com'
conn = Connection(server, the_user, password='adminpass')
conn.bind()

user = 'cn=testuser,ou=People,dc=domain,dc=com'
conn.extend.microsoft.modify_password('cn=testuser,ou=People,dc=domain,dc=com', None, 'newpassword')
print(conn.result)

ldap3.core.exceptions.LDAPAttributeError: invalid attribute type in attribute