There are ways to use the gcloud API and SDK to run the GCP API.
Use a service account created with GCP. Since there is OAuth 2.0 authentication, API is accessed after getting a token. However, there was also a method of requesting the API directly without taking a token by encrypting the authentication information and embedding it in the http request header. I think that the latter is more familiar with how to make JWT, so this time I will use it.
The OS used was CentOS7 of Linux.
In this article, we will skip creating service accounts. Please see https://jwt.io/introduction/ for details.
(Reference: Call using HTTP / REST
https://developers.google.com/identity/protocols/OAuth2ServiceAccount#authorizingrequests: