wpmem_post_update_data

add_action( 'wpmem_post_update_data', function( $fields, $user_id ) {

    // Example to display the contents of the array.
    // Uncomment to use.
    // echo "<pre>"; print_r( $fields ); echo "</pre>";
    // exit();

    // Example of setting a custom meta field.
    $meta  = 'my_meta_field';
    $value = 'some value';
    update_user_meta( $fields['ID'], $meta, $value );

    // Note this is an action, so nothing needs to be
    // returned from the function.
    return;
    
}, 10, 2 );