403 Forbidden on OAuth Token but Application Token works fine

[good.buyer]

Hi, I am testing my API calls in API Explorer. When I generate an Application Token, it works fine; but, when I try the same using an OAuth Token or Auth'n'Auth token, I get an error saying 403 response. The response I get is:

"errors": [
{
"errorId": 1100,
"domain": "ACCESS",
"category": "REQUEST",
"message": "Access denied",
"longMessage": "Insufficient permissions to fulfill the request."}
]

Has anyone of you encountered this same issue and were able to find a fix?

I am wanting to use an Auth'n'Auth token because it is not short lived, to make API calls from my web server to get the list of items from eBay.

[developer_support@ebay]

Hi @good.buyer 

The eBay token service generates, or mints, OAuth access tokens via two different grant flows:

• Client credentials grant flow mints a new Application access token that you can use to access the resources owned by the application.
• Authorization code grant flow mints a new User access token that you can use to access the resources owned by the user.

You can refer to the OAuth scope section in API Documentation to see the supported access token and scope for that call. If you use the incorrect access token, the call will fail with error "Access denied".

[nextmotopartsusa]

I have a similar problem, but on the website I can click and obtain the token to validate my endpoints, but when making the call to the token programmatically, it does not accept it and gives the error
{
    "errors": [
        {
            "errorId": 1100,
            "domain": "ACCESS",
            "category": "REQUEST",
            "message": "Access denied",
            "longMessage": "Insufficient permissions to fulfill the request."
        }
    ]
}

I am going through the following steps to get the token
url https://api.ebay.com/identity/v1/oauth2/token
parameters
scopes
grant_type

in addition to also passing Authorization, basic with code64

generates the token, in the following structure

    "access_token": "v^1.1#i^1#I^3#p^1kNO/kXBn35D9ohfWgGEQAA....",
    "expires_in": 7200,
    "token_type": "Application Access Token"


But when passing this token to the endpoint call, it gives the error message I put above, would anyone know what it could be, or have you experienced this?