...
Download the OneList API definition file:
/onelistserver/swagger/integration/swagger.json. Note, the integration JSON is available from OneList v6.5.2.Follow the instructions in Create a custom connector from an OpenAPI definition and import the above JSON file to create the connector for OneList.
Enter the OneList host url, e.g. iqx.onelistapprovals.com
Select the Next button then Click the “Update connector” at the top of the page to save the connector.
...