For PC:
1)Microsoft Smartscreen sometimes prevents you from downloading.
Search "how to turn off SmartScreen" at Google.
2)Press F12 or Ctrl+Shift+I to turn on "Developer Tools".
Switch to "Console" and contact developers of the itch.io if there are some Javascript errors.
For Android:
1)Switch your browser to Chrome,Firefox or Edge and retry.
2)Turn on your VPN.
3)Ask someone to help you download.