This topic explains where the data is. After making any significant changes in Freeter, I always make a copy of the folder. (It also allow me to transfer workflows to another computer.)
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://)
For a one-off donation - you might just complete the payment and then cancel the membership. Every bit of support really helps and is much appreciated!