This will allow the Arduino IDE to program the Digispark controllers.
In the top left hand corner change the Type to “Contributed” and click the install button on the “Digistump AVR Boards by Digistump package”.Once installed, go-to Tools –> Board and select “Board Manager.This is done by opening the Arduino IDE, clicking on ‘File, Preferences’ and adding the following URL into the ‘Additional Boards Manager URL’s’ box, then click ‘OK’.