How to connect google sheet as a external database for Wix

https://support.wix.com/en/article/corvid-adding-and-deleting-an-external-database-collection

"In the Add External Database Collections screen: 1. Give your namespace for the collections a name 2. Enter your SPI's endpoint URL 3. Add any necessary connection data to the Configuration (ex: user name, password, secret key)"

What is SPI? And what is google sheet's SPI?