I currently use Cal.com for scheduling multiple types of appointments that clients pre-pay for with Cal.com's integrated payment processing. There are multiple different meeting platforms that can be integrated to host the virtual meetings, including Zoom or Google Meet, but I would prefer to use something secure like Proton Meet.

Proton Calendar’s scheduling and booking page cannot accommodate the robust multiple types of booking at multiple different prices and durations, and possibly cannot be changed to handle payment processing due to encryption/security standards…so in lieu of this, could Proton Meet simply be available to integrate with Cal.com? This would allow meetings to be confirmed by email with a link to the Proton Meet meeting instead of having to manually send separate and conflicting information and create confusion about which link/virtual meeting host is preferred.