how a external user can get in to odoo system with credential using API keys?

suppose user A is a customer he want to approve something in the odoo system , but he don't have credential to the odoo , then how the user can login using the API Key?

is that possible ??
i tried uisng xmlrpc but its just working in the command Prompt.

import xmlrpc.client

url = "http://localhost:8071/"
user_name = "demo@systems.com"
password = "33cedd25d3a80aeb1ba220f935353a2aa55c0fe1"
db_name = "Timesheet_new"

try:
    # Common authentication check
    common = xmlrpc.client.ServerProxy('{}/xmlrpc/2/common'.format(url))
    uid = common.authenticate(db_name, user_name, password, {})

    if uid:
        # Additional checks
        models = xmlrpc.client.ServerProxy('{}/xmlrpc/2/object'.format(url))

        # Try to fetch user details
        user_details = models.execute_kw(
            db_name, uid, password,
            'res.users', 'search_read',
            [[('login', '=', user_name)]],
            {'fields': ['active', 'login', 'name']}
        )

        print("User Details:", user_details)

except Exception as e:
    print("Detailed Error:", str(e))

its only working on the cmd , how make it working for the external user in to the odoo website??