When prompted Select Application Type as Desktop App and click Create to receive your ClientID and Secret. You can use this information now to configure Connection with UseCustomApp=true.
NOTE: If you are planning to use your current data connection/token for automated processes, we recommend that you use a generic account for token generation when the login box appears (e.g. sales_automation@mycompany.com instead of bob_smith@mycompany.com). When you use a personal account which is tied to a specific employee profile and that employee leaves the company, the token may become invalid and any automated processes using that token will fail. Another potentially unwanted effect of using a personal token is incorrect logging; the API calls (e.g. Read, Edit, Delete, Upload) made with that token will record the specific user as performing the calls instead of an automated process.