The first field does not accept http or https data. You can only use the " /" for the index page or " /blog " etc for secondary pages and link those to an external source. If it is an old domain that you own and would like to redirect it to a new domain, you will need to do one of the following:
Use GoDaddy 301/302 redirect conventions to perform this, or
Add the old domain to your webflow project and then setup the redirect policy there.