Open the Sites upload tool
When a project starts with a list of places - schools from a ministry register, sites from a planning spreadsheet - create them all at once instead of one by one. The same tool updates existing sites: download the current list, change what you need, upload it back. New to sites? See What is a site?
On the project dashboard select the gear → Project Settings.
Expand BULK UPLOAD AND UPDATE and select Sites.
The SITES page has two tabs - UPLOAD for sending a file and TEMPLATE for getting the blank spreadsheet - and a Download Sites button at the top right that exports the sites you already have (used on the last page).