###UPDATE(April 2019)
UPDATE(April 2019)
You can now directly insertCheckboxes(or removeCheckboxes) on a Range or RangeList without any workarounds. You can also change the checked value/unchecked value using alternate method signatures found in the documentation.
###Snippet:
Snippet:
SpreadsheetApp.getActive() .getRange('Sheet2!A2:A10') .insertCheckboxes();