Guidance on making OAuth work for the Wallabag API

I am trying to get the OAuth2 option of the HTTP Request node to work with the Wallabag API (https://doc.wallabag.org/en/developer/api/oauth.html). I have already OAuth working on my n8n instance for various other services from Google, Microsoft etc.

I simply cannot get OAuth to work with this particular API and I always get an invalid credentials error. However, When I try the same call via Postman or rest-client on VSCode, a token is successfully generated. Given below are the working calls I can make outside of n8n (This API allows POST and GET calls for OAuth).

POST https://domain.com/oauth/v2/token HTTP/1.1
content-type: application/json
{
    "username": "username",
    "password": "password",
    "client_id": "client_id",
    "client_secret": "client_secret",
    "grant_type": "password"
}

OR

GET https://domain.com/oauth/v2/token?username=username&password=password&client_id=client_id&client_secret=client_secret&grant_type=password HTTP/1.1

Given below is my credential setup on n8n, which never seems to go through when I initiate the OAuth connection.

Could someone please guide me on where I could be going wrong?

Yes, this grant type it’s currently not supported. Just the grant type authorization code is supported. You can make a feature request.

Ah, I see. Thank you for your prompt response, @RicardoE105!
I’ll make a feature request :+1:

Are there any plans to add support for additional grant types?
We would like to use the HTTP request but we need to use Grant_Type=Client_Credentials.

@craigbechelli welcome to the community.

There is no plans yet but you can always make a feature request. The more votes the more chances of being developed