Try this ode, dont forgot to change
ex: http://test.com/custom_page
custom_page => ( Change with your current registration page slug )
change this link
‘http://customlink.com/asdasda/‘ => (Change with where you want to redirect )
$registration_redirect=”http://customlink.com/asdasda/“
add_filter( 'registration_redirect', 'my_redirect_home' );
function my_redirect_home( $registration_redirect ) {
global $post;
$post_slug=$post->post_name;
if( 'custom_page' === $post_slug ){
$registration_redirect="http://customlink.com/asdasda/";
}
return $registration_redirect;
}