Sync column in two different spreadsheets from imported data

I have a private spreadsheet and a shared spreadsheet with data imported from the private one. I want users to be able to make changes to the shared spreadsheet, that will reflect on the private one. For example, I would like users to be able to uncheck column A cell 1 here (https://docs.google.com/spreadsheets/d/1JX6XFGJksanTPIrN7oqVf1iDDIxXeFDG8Xq3iHXGEBo/edit?usp=sharing) and have the change reflect on the private spreadsheet here (https://docs.google.com/spreadsheets/d/16FJzFqWkyN9vy2E3IFpaifybwfdoq-iLj_qKZsnQau8/edit#gid=0)

=IMPORTRANGE("16FJzFqWkyN9vy2E3IFpaifybwfdoq-iLj_qKZsnQau8", "Sheet1!A1:U1000")

I expect to be able to change data in shared spreadsheet and have it reflect on the private spreadsheet