[Dialogflow] Authenticate with API Key

Hello, I want to use dialogflow api within my project (for Gen App chat bot). But the authentication seems weird.

My server is hosted in Azure and most of third parties I use connect with API Token or API Key. Here with dialogflow I can't find any documentation mentioning it.

I don't want to authenticate with ADC, because it's complicated, unaesthetic, requires files from what I have understood so far. I just want to have a simple API key that I can provide to the client and then call my chatbot. Simple.

Here is the current code :

const sessionClient = new dialogflow.SessionsClient({
  projectId,
});

export async function getUserIntent(
  sessionId: string,
  query: string,
  contexts: any,
  languageCode: string = 'fr'
) {
  const sessionPath = sessionClient.projectAgentSessionPath(
    projectId,
    sessionId
  );

  const request = {
    session: sessionPath,
    queryInput: {
      text: {
        text: query,
        languageCode,
      },
    },
    queryParams: {},
  };

  if (contexts && contexts.length > 0) {
    request.queryParams = {
      contexts,
    };
  }

  const responses = await sessionClient.detectIntent(request);
  return responses[0];
}

But I have the following error :

Error: Could not load the default credentials. Browse to https://cloud.google.com/docs/authentication/getting-started for more information.
    at GoogleAuth.getApplicationDefaultAsync (C:\dev\repos\raskyer\la-plateforme\web\node_modules\google-auth-library\build\src\auth\googleauth.js:207:19)
    at processTicksAndRejections (node:internal/process/task_queues:95:5)
    at GoogleAuth.getClient (C:\dev\repos\raskyer\la-plateforme\web\node_modules\google-auth-library\build\src\auth\googleauth.js:624:17)
    at GrpcClient._getCredentials (C:\dev\repos\raskyer\la-plateforme\web\node_modules\google-gax\build\src\grpc.js:145:24)
    at GrpcClient.createStub (C:\dev\repos\raskyer\la-plateforme\web\node_modules\google-gax\build\src\grpc.js:308:23)

googleapis / google-cloud-node

[Dialogflow] Authenticate with API Key #4692