Error: "message":"Unable to save details","url":"/magento2/setup","code":500
The issue here can be that the store URL within Shiptheory was incorrect. Changing this in the Shiptheory UI to match the actual store URL will fix this issue.
To do this:
First, find the URL for your magento2 store and copy it.
Then, navigate to magento2 integration settings within Shiptheory.
Once in there, paste your store URL into the Magento 2 Store URL field and save your changes!
If you have tried this and are still experiencing issues, then do not hesitate to get in contact with us at support@shiptheory.com or call us on 0117 403 4313.