Doesn’t seem to work

You need to register customer first using plugin’s mobile number field.
Not any mobile number stored on your website can be used for login

Yes, its possible.
Saving numbers for login is more complicated than simply saving them in a field.
For login purpose, we need to check whether the number is already used before or not, plus there is a possibility of two same phone numbers with different country code.

I can share the snippet to merge phone number fields. Are you using woocommerce?
Where are the numbers stored? It should be in WC’s billing phone field.

No, merging will simply copy your WC’s billing phone field to plugin’s phone field.
It is not going to affect your site in anyway even if you abort or re run the code.
Completely safe.

(Goes in functions.php)

1) Change +91 below to your country code if not India
2) Visit http://www.yourwebsite.com/wp-admin/admin.php?page=xoo-ml, the code will run & it may take few seconds to load page.
Once the page is loaded, you can remove the code.

add_action( 'init', function(){
 
 
            if( !is_admin() || wp_doing_ajax() || !isset( $_GET['page'] ) || $_GET['page'] !== 'xoo-ml' ) return; // run only on otp settings page
 
            $args = array(
                'role'    => 'customer',
            );
 
            $users = get_users( $args );
 
            $phone_code = '+91';
 
            //loop users
            foreach ( $users as $user ) {
 
                       
                        $billing_phone = get_user_meta( $user->ID, 'billing_phone', true ); //Get billing phone
 
                        if( !$billing_phone ) continue; // switch to next user if billing phone is empty
 
                        update_user_meta( $user->ID, 'xoo_ml_phone_code', $phone_code ); //Update phone code required for login
 
                        update_user_meta( $user->ID, 'xoo_ml_phone_no', $billing_phone ); //Update phone number required for login
 
                        update_user_meta( $user->ID, 'xoo_ml_phone_display', $phone_code.$billing_phone ); // Just for display
 
            }
 
} );

• This reply was modified 2 years, 8 months ago by xootix.
• This reply was modified 2 years, 8 months ago by xootix. Reason: Code updated

Please copy the code again, I updated it few minutes later after posting.