I have been able to authenticate using the json file associated with a service account using googleAuth and bigQueryR.
googleAuth
bigQueryR
# Load Packa
set_service_token() is now deprecated.
set_service_token()
Use bq_auth() instead:
bq_auth()
bq_auth(path = "location_of_service_token.json")
Source: https://rdrr.io/cran/bigrquery/man/bigrquery-deprecated.html