[dev] Problems in Customer Update

I am using following syntax as mentioned in dev.otrs.org to update Customer $CustomerUserObject->CustomerUserUpdate( Source => 'CustomerUser', # CustomerUser source config ID => 'mh' # current user login UserLogin => 'mhuber', # new user login UserFirstname => 'Huber', UserLastname => 'Manfred', UserPassword => 'some-pass', # not required UserEmail => 'email@example.com', ValidID => 1, UserID => 123, ); Unfortunately, I am not able to update customer. I would like to know the values that I should enter in these fields ID, and UserID Thanks, Jignesh