Easiest way imo is to use a time-based built in trigger for the Sheet, selecting the function you want to run on the time-based trigger, as shown here: https://help.databox.com/how-to-refresh-a-google-sheet-using-google-apps-script

Can create many different triggers to run different functions, or the same functions on different schedules, or a combination thereof.

This works well for me for the use-case of refreshing asset price data fetched once every 10 minutes.