There is also a note in the app that it is not a public URI: All your redirect URIs should be publicly reachable, these aren’t: http://localhost:5678/rest/oauth2-credential/callback
It is clear that it is not public because I host n8n via docker. So I don’t think this is the cause of the error.
Ensure to copy your n8n workflow and paste it in the code block, that is in between the pairs of triple backticks, which also could be achieved by clicking </> (preformatted text) in the editor and pasting in your workflow.
```
<your workflow>
```
That implies to any JSON output you would like to share with us.
Make sure that you have removed any sensitive information from your workflow and include dummy or pinned data with it!
Have you followed Miro documentation on creating Miro app to acquire access token, Quickstart? Not sure what the 2nd screenshot has to do with this process.
As for HTTP Request configuration, you would need to use Miro API URL which seems to be something like this, https://api.miro.com/v2/boards.
