When you are trying to connect your iCloud calendar in Vectera you will have to create an App-specific password. Follow these steps to create this one time password:
Fill in your Apple email address and password and click on the arrow
A pop-up will show that says 'Your Apple ID is being used to sing in to a new device', click on allow.
4. Now you will get a code that exist of 6 numbers. Type that code in the Apple sign in page boxes:
5. In the middle of the page you will see Security. There you can change your password and trusted phone number, activate a 2FA and generate an App-specific password. Click on Generate password and type Vectera in the pop-up box
6. Copy the password and paste it in the pop-up in Vectera.
7. Now you've created an App-specific password to connect your iCloud calendar in Vectera. Follow the steps from this help article to continue.