Can you describe what you are trying to accomplish, and show the exact URLs you are calling? For normal integration you may not need to go through the full OAuth web flow. Instead, if all you need is for your program to call our API and use a single login, just use the generic access token. Generate it at
https://bitly.com/a/oauth_apps, store it in a config file or hard-code it, and don't worry about dynamic OAuth authentication. The only reason you would need to implement the OAuth web flow is if you intend your application to be used by folks who each have their own Bitly account. If that _is_ your use case, then we'll need to see the details of the OAuth web flow endpoints you are calling. Perhaps at that point, we should move to a private email conversation at
a...@bitly.com in order to avoid exposing your security details on the public internet.
Sr. Backend Engineer