I am currently creating a creator application that will automatically get a Sprint, create a Sprint, etc. from an API of another website. Now, in the developer console, I was given the option to add a client. I selected, Self Client.

I then generated a code using this.

But when I tried to use it in my function,

I get this result.

Can you tell me where I am getting this wrong? Provide me an example or any guide that will help me make this work. Thank you.