Hello, O
It's caused because of the incorrect web server configuration. To make iola work with your website you should update the content of your .htaccess file that is located in the root Oxwall directory. Add to the bottom of this file these rows:
# Authorization header (support iola app authorization)
SetEnvIf Authorization "(.*)" HTTP_AUTHORIZATION=$1
After you update .htaccess file everything should work fine (there is no need to reload web server). Let us know if you'll face with any difficulties or this method will not fix your problem.
About Website URL: if you don't want to enter Website URL you'll probably want to buy our "Steady Growth" plan (but currently it's in development). Please see more info here: https://iola.app/#pricing
P/S We've created the special Support Questions topic for reports/questions like this so please ask your further questions in that topic.
After your response here we'll delete this topic to prevent cluttering the forum.
Thank you.