Billing Features
It is required to setup an account for billing purposes. This account should be associated with all projects related. This is required to setup additional features for the GCP like Sendgrid integration and platform support.
Link a billing account
Dashboard
Sendgrid
Get into:
https://cloud.google.com/appengine/docs/standard/java/mail/sendgrid?authuser=1
Click in Sign In to Sendgrid using GCP user.
Console: