I got "invalid_grant" error on trying to request to the token endpoint using OAuth2

AI generated answer (using internal Slack threads):

The "invalid_grant" error in OAuth2.0 usually occurs when the authorization code, client ID, or user credentials are not correct. It can also happen if the redirect URI does not match the one that was included in the initial authorization request. In the context of NetSuite, make sure that the scope of your token includes the necessary permissions. For example, if you're trying to access a RESTlet, the scope of the token should include 'restlets'. Also, ensure that your authorization code, client ID, and redirect URI are all correct and match what was included in your initial authorization request. If you're using Postman, make sure you're correctly setting up the OAuth 2.0 settings and that you're sending the request to the correct endpoint. ****** Disclaimer: This response was generated by an artificial intelligence assistant based on previous conversations from multiple Slack channels, and may contain inaccuracies or mistakes. ******