Auto Refresh IFRAME (external data source) with Javascript

[Initiostar]

I am working on a project that can display live data (from Google via a Google Sheet). The iframe correctly refreshes the data when you first load the web page. I would like however to auto-refresh the iframe (not the page) using a time function around 5s.

It appears there are a myriad of different javascript solutions to fix this, but I would welcome any input that keeps it simple.

Thanks Gary