There's a new version of the HubSpot API

As of November 30, 2022, HubSpot API keys are no longer a supported authentication method for accessing HubSpot APIs. Instead, you should use a private app access token or OAuth to authenticate API calls. Learn more about this change and how to migrate an API key integration to use a private app instead.

How do I find the app ID for a HubSpot app?

Your app ID can be found below the name of your app when viewing the Apps dashboard in your developer account.

app_id_list

The app ID is also displayed when viewing the auth settings for your app.

app_auth_id_settings