How to get a "Https" url for my IPN Listening Url

I'm using the Paypal Standard gateway to process signup through Membership 2 Pro. The plugin gives me a "http" url to put into my PayPal profile, but there's notice on the PayPal configuration page that says PayPal only allows "https" urls for the IPN Listening url.

How do I get a "https" from the Membership 2 Pro plugin?