https://www.sharepointgems.com/2022/05/solved-the-api-sharepointonline-returned-an-invalid-response-for-workflow-operation-get_items-of-type-openapiconnection-error-details-the-api-operation-getitems-is-missing-requi/
Solved: The API ‘SharePointOnline’ returned an invalid response for workflow operation ‘Get_items’ of type ‘OpenApiConnection’. Error details: ‘The API operation ‘GetItems’ is missing required property ‘.