On iOS 14 device (test with iPhone 7 / iOS 14.0 / Safari) it works fine only once. For the second time it throws permission error:
Code Block Error: NotAllowedError: The request is not allowed by the user agent or the platform in the current context, possibly because the user denied permission.
Here are all the steps to reproduce:
Go to MDN Webshare API
Find a link to Web share test in "Examples" section and open it
Click "Share MDN!" button
Choose one of suggested options or just close sharing popover
Click on "Share MDN!" button again
See the error