Made by Reddit user /u/ARM64-darwin1820 are two iOS shortcuts that enable users to download checkra1n on their phone, and then AirDrop it to their Mac/Hackintosh.
Currently, the mobile website of checkra1n.in does not allow you to download the jailbreak, with the shortcut however, it will download the latest version, and then prompt you with the share sheet.
The 2nd shortcut simply sends you a notification with the latest checkra1n version and will notify you if there is an update.
In order to correctly install the shortcuts, ensure you have Allow Untrusted Shortcuts toggled on in your Shortcut settings.
Here are the download links: