To connect your iCloud calendar to Vyte, you need to generate an app-specific password for it.
To generate an Apple app-specific password:
Sign in to appleid.apple.com with your Apple ID
In the "Sign-in and Security" section, go to "App-Specific Passwords"
Click on "Generate an app-specific password" or the Add button "+"
Give a name to that password (ex: "Vyte") then click on "Create"
Copy the password that has been generated
If you forget your app-specific password, you can always find it listed in the "App-Specific Password section"
Now that you have your app-specific password, you can proceed to connect your iCloud calendar to your Vyte account.