The solution here would be to set the widget to the main login page initially, then once the Freeter browser instance has the tokens, you should be able to change it to the target URL you want.
I know this is kind of old, but I set up freeter today, and I used ip addresses + ports for both Link Openers AND Webpages. They both work fine. Are you making sure to use the protocol? (i.e. https://)
