Hi @zach8 , Good luck!
The error is a generic Bubble error that usually occurs because the plugin has an issue such as an incorrect input in one of the fields.
Try following these steps to see the server logs which will show a more useful error: Troubleshooting & Support - Interwebb.co.uk - Bubble.io Plugin Docs
Also, it’s best to discuss the Square Online Checkout plugin in it’s dedicated forum post here: [New Plugin] Square Checkout - By Interwebb - Showcase - Bubble Forum
Regarding the webhooks, you’ll need to set up the workflow API root URL and Backend Workflows in your bubble app to enable an endpoint URL and then configure this in Square to receive the webhook notifications when an event happens.
Let me know if you’re still stuck with the error and I’ll be happy to help!
Thanks,
Phill