Short answer: you can't.
Jackbox Games does not control the various stores and marketplaces where our games are sold and as a result, you can’t transfer purchases between platforms. In order to have the game on a new platform, you must purchase the game on that platform.
However, there is one exception to this rule: When purchasing from the Mac App Store, the Apple TV (tvOS) version of our games can also be played on iPads (iOS), and vice versa. The Jackbox Party Pack 7 is the first title we have been able to offer as a universal purchase on the Mac App Store. This means a single purchase (from the Mac App Store) gives one access to the game across MacOS computers, iPad devices, and Apple TVs. Prior to Pack 7, the Mac OS version requires a separate purchase from the Mac App Store.