[BUG][csharp] Bearer token not added when using AccessToken configuration

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

Using either of these two configurations does not set the Authorization: Bearer <access_token> header.

var configuration = new Configuration
{
    AccessToken = accessToken
}

var configuration = new Configuration
{
    ApiKeyPrefix = new Dictionary<string, string>
    {
        { "Authorization", "Bearer" }
    },
    ApiKey = new Dictionary<string, string>
    {
        { "Authorization", accessToken }
    }
}

But using DefaultHeaders seems to work. This is counter intuitive - the AccessToken configuration property should either be fixed or removed.

// This works but it is ugly
var configuration = new Configuration
{
    DefaultHeaders = new Dictionary<string, string>
    {
         { "Authorization", $"Bearer {accessToken}" }
    }
}

openapi-generator version

openapitools/openapi-generator-cli:latest

OpenAPI declaration file content or url

https://api.signicat.com/info/lookup/swagger/v1/swagger.json

Generation Details

docker run --rm --volume "${PWD}:/generated" openapitools/openapi-generator-cli generate \
    -i https://api.signicat.com/info/lookup/swagger/v1/swagger.json \
    -g csharp \
    -o /generated \
    --additional-properties=targetFramework=net8.0

Steps to reproduce

1. Run the docker command above
2. Set the authorization token either with the AccessToken configuration property or by the ApiKeyPrefix + ApiKey configuration properties.
3. Send a request
4. Inspect the request headers
5. See that Authorization: Bearer <access_token> is not present

Related issues/PRs

Suggest a fix

Remove the non-working configuration properties or fix them.

Reproduce the issue with the provided Docker generation command and the Signicat OpenAPI document, targeting csharp. Start at the generated Configuration entry point and the request authentication handling for AccessToken, ApiKeyPrefix, and ApiKey. Done means generated requests include the expected Authorization: Bearer <access_token> header, with regression coverage for the affected configuration.