Inspect the home page for find the App version for downloading supported Extension tool if used App version – 2021.2.0.108 then supported extension version is Extension Development Tools -21.2.x.zip from the bundle version is SuiteBundles/Bundle 390093/. Download the .zip file you find there: go to root file Run 1. npm install 2.gulp Extension:fetch 3.create Extension… Continue reading Set Up Extension Developer Tools Supporting versions