Authenticate

curl --request POST \
  --url https://auth.vatis.tech/realms/vatistech/protocol/openid-connect/token \
  --header 'Content-Type: application/x-www-form-urlencoded' \
  --data 'client_id=<string>' \
  --data 'client_secret=<string>' \
  --data grant_type=client_credentials

{
  "access_token": "<string>",
  "expires_in": 123,
  "token_type": "<string>"
}