Follow these steps to obtain your Google Account token.

Login to your Google Account
Go to:
1. Cloud customers: https://app.frevvo.com/google/consent
2. In-house customers: http://<your frevvo server domain name>/google/consent
Click Allow if you see a screen like the one below (Google often updates their UI so this may differ from what you see).
Copy the access token. Save it to a safe location, you will use it when configuring your forms/flows.

You must obtain a Google access token for every Google Account you wish to use with your forms/flows. Repeat steps #1-4 above for each Google Account.
In-house customers with multiple servers must obtain Google Access Tokens for each server / Google Account.
Google limits the number of access tokens per Google Account. If the token limit is exceeded, older refresh tokens stop working.
Google may revoke Access Tokens unused for ~6 months. If this happens you must obtain a new new token and update your forms/flows.

Google Sheet Best Practice

Create a dedicated Google user to own all the Google Sheets integrated with your forms/flows. This is recommended to:

Reduce the list of Google Sheets available in the form/flow Google Wizard dropdown to only those used for frevvo/Google integration.
Reduce integration breaks with your forms/flows due to another Google user changing a column name, tab name or deleting a tab or Sheet.

Browser not supported