Oauth2 token request missing Basic credentials with openapi-generator generated java code

Question

I'm trying to use generated (java) code with openapi-generator to access oauth2 securized api endpoints.

Generated code is done with open-api-generator-maven-plugin with pom :

<build>
    <plugins>
  <plugin>
    <groupId>org.openapitools</groupId>
       <artifactId>openapi-generator-maven-plugin</artifactId>
        <version>5.4.0</version>
        <executions>
            <execution>
                <goals>
                    <goal>generate</goal>
                </goals>
                <configuration>
                    <inputSpec>/home/git/scpec.json</inputSpec>
                    <skipValidateSpec>true</skipValidateSpec>
                    <generatorName>java</generatorName>
                    <generateApiTests>false</generateApiTests>
                    <generateModelTests>false</generateModelTests>
                    <apiPackage>test.storage.api</apiPackage>
                    <modelPackage>test.storage.model</modelPackage>
                    <configOptions>
                    </configOptions>
                </configuration>
            </execution>
        </executions>
    </plugin>
    </plugins>
</build>

The generated code seams to be welll formed. To use the generated code i'm running the here under exemple :

    HashMap parameters = new HashMap<>();
     parameters.put("scope","perf");
    parameters.put("login","user-login");
    parameters.put("password","xxxxxxxxxxxxxxx");
    parameters.put("grant_type","password");
    ApiClient client = new ApiClient(url, "clientId", "clientSecret", parameters);
    PluginControllerApi api = new PluginControllerApi(client);

    List<EntityModelString> types = api.getPluginTypes(true);

    Assertions.assertTrue(!types.isEmpty());

The generate code is generated with the here under spec :

{
  "openapi": "3.0.1",
  "info": {
    "title": "Storage service",
    "description": "Files storage management",
    "license": {
      "name": "GPL-3.0"
    },
    "version": "1.0.0"
  },
  "servers": [
    {
      "url": "http://myserver/api/v1/rs-storage",
      "description": "Generated server url"
    }
  ],
  "security": [
    {
      "REGARDS_OAUTH2": []
    }
  ],
  "paths": {
    "/plugintypes": {
      "get": {
        "tags": [
          "plugin-controller"
        ],
        "operationId": "getPluginTypes",
        "parameters": [
          {
            "name": "available",
            "in": "query",
            "required": false,
            "schema": {
              "type": "boolean"
            }
          }
        ],
        "responses": {
          "200": {
            "description": "OK",
            "content": {
              "application/json": {
                "schema": {
                  "type": "array",
                  "items": {
                    "$ref": "#/components/schemas/EntityModelString"
                  }
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "EntityModelString": {
        "type": "object",
        "properties": {
          "content": {
            "type": "string"
          },
          "links": {
            "type": "array",
            "items": {
              "$ref": "#/components/schemas/Link"
            }
          }
        }
      },
      "Link": {
        "type": "object",
        "properties": {
          "rel": {
            "type": "string"
          },
          "href": {
            "type": "string"
          },
          "hreflang": {
            "type": "string"
          },
          "media": {
            "type": "string"
          },
          "title": {
            "type": "string"
          },
          "type": {
            "type": "string"
          },
          "deprecation": {
            "type": "string"
          },
          "profile": {
            "type": "string"
          },
          "name": {
            "type": "string"
          }
        }
      }
    },
    "securitySchemes": {
      "REGARDS_OAUTH2": {
        "type": "oauth2",
        "flows": {
          "password": {
            "tokenUrl": "http://myserver/api/v1/rs-authentication/oauth/token",
            "scopes": {
              "perf": ""
            }
          }
        }
      }
    }
  }
}

When i run my test code, the client api call the configured endpoint to authneticate but in the oauth/token@POST request sent the header "Authorization: basic xxxxxxx" (where xxxx is clientId:clientSecret coded in base64) is not proovided. This header is needed by oauth2 to authenticate the client before authenticate the user.

Is there a way to configure anything to add this header in the oauth2 token request ?

Thanks.

EDIT : It seems that my question is related to an opend issue : https://github.com/swagger-api/swagger-codegen/issues/7648. Is there any fix planned ?