Access Code not working when calling /oauth2/authorize with call back URL

[saqib-shafique]

 I have made an API which calls /oauth2/authorize to get access code which is used to get access token and refresh token, since this will be used in an automated process, when I call /oauth2/authorize without callback url, the code I get it works by copying and using in

/oauth2/token, but if I use it with callback URL it always returns "response_body": "{\"error\": \"invalid_grant\", \"error_description\": \"code has already been used\"}".
Call back url(http://localhost:5000/callback) is configured correctly, otherwise it should not be working when using code manually. 

https://www.dropbox.com/oauth2/authorize?client_id={CLIENT_ID}&token_access_type=offline&response_type=code&redirect_uri={REDIRECT_URI}
"grant_type":"authorization_code"

any assistance will be really helpful.

[Здравко]

Hi @saqib-shafique,

As the error message says, you have tried your code more than once. 🙂 This code is for single time use only. Even more - if not some copy/paste mistake, your URL is incorrect. The ending ("grant_type":"authorization_code") has nothing to do there. If you cannot get in touch/understand with your error, post relevant code snippet letting the mistake reproduction here, so we may comment it. 😉