Frappe.call() giving error 'ReferenceError: membership_loyalty is not defined'

i created a whitelist method called change_password() at the directory

/frappe-bench/apps/membership_loyalty/membership_loyalty/change_password.py

and the change_password.py contains a function called change_password()
so I am calling the change_password() using frappe.call()

but it is giving the error ‘ReferenceError: membership_loyalty is not defined’
here is the whitelisted method

why I am getting the error?