How to sync Calendly app with iCal? Best approach for online scheduling?

Hi folks,

I am searching for a great online scheduling app—one that I can embed in my website and sync, ideally, with iCal across devices—that will allow people to schedule and pay for time with me. After some quick research, I decided to try Calendly but am immediately having trouble syncing it with iCal.

Calendly gives the following instructions (to generate an app-specific password for integration):

1. Sign into your iCloud account
2. In the Security section, click edit
3. Click Generate Password and follow the steps there. Once you've generated the password, you will be able to login to Calendly.

When I get to Step #3, I see no option to generate a password, only to change my existing password.

Has anyone had success integrating Calendly with iCal? How do I do it? If not, what other scheduling tool would you recommend? Or do I need to switch to Google Calendar like the rest of the world? : (