Secure BigQuery Service account shared key usage in non GCP application

Question

I have request from users to be able to connect to my datasets and table in BigQuery to fetch the data and manipulate it programmatically outside of GCP.

The situation now that I created a service account with credentials to view data and i share the JSON key of this service account with users in email.

1. I want to avoid users to use the key inside their code

2. best way to secure sharing this key with them