Long-time listener, first-time caller!

I am creating a form to allow users to request a bus pass, and the admin team processing these requests has asked that the form add rows to an existing SharePoint List they use to keep an inventory of in-use and available passes. My thought was to have the Laserfiche Form call a Workflow that includes the Create List Item activity, but I'm having trouble establishing the server for the web service.

I pasted the root of our SharePoint site into the URL field, but I'm getting an error "Server was unable to process request. --> Access is denied. (Exception from HRESULT: 0x80070005 (E_ACCESSDENIED))." Have others experienced and managed to resolve this error? I tried it with default authentication and hard-coded credentials with elevated access, and the result in the same, so not sure what else to troubleshoot. We're using Laserfiche on-prem and SharePoint Online. Workflow Designer is v11.0.2306.898.

Thanks!

Megan Bermudez