A private integration for your own Drip account and a public integration for other customers should not collect credentials in the same way. Drip's authentication guide documents a private API token as the HTTP Basic username with an empty password, and OAuth for public integrations.
In the Drip API discussion, state which type of application you are building before troubleshooting authentication. Keep private tokens on the server and out of support examples.
Start with a read-only operation against the intended account. Testing a connection should not accidentally enroll real contacts in a messaging workflow.
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