Author website URL

you need to assign $curauth and since you are not on an author archive but on a regular page you can use get_userdata function and pass the user ID like so:

$curauth = get_userdata(1);
//and then use 
echo $curauth->user_url;

or if you are in the loop you can use the_author_link(); which will Displays the author’s Website URL as a link and the text for the link is the author’s Profile Display name publicly as field.