In case anyone else encountered this problem. You have to edit your function and check the "has return value" box. Then your return will work. After this you have to use "Call Function" again and now you have a new field for saving results.
@Diya.3rif twitter email is a little bit tricky. They have fake url in email.
Anyway I prepared code for you that extracts url param from original url.
It uses split function to exctract query param like this
