Go to Administration -> Application links and click on Create Link
Create an External application link with Incoming Direction
Configure it as follows
Name: choose any name
Redirect URL: https://<your-jira>/plugins/servlet/senora/redirect
Permission: Write
Save
Open the newly configured Application link by clicking on the three dots menu and then View Credentials
Open in a new browser tab or page the Manage Apps tab
Open Configure Connection under the SHAREPOINT CONNECTOR FOR JIRA section
Copy and paste from the Application Link credentials both the Client ID and Secret in the relative sections
Save