The site seems very secretive about how it works. After reading a while, here is my educated guess:

To use it, the user first needs to get ahold of Bitcoin SV somehow.

Then the user needs to install their software.

Since the software allows "payments" to people who do not have a public Bitcoin SV address, I guess the payment goes to PeerSend and not to the receiver.

PeerSend then tries to contact the receiver and convince them to make a Bitcoin SV address.

If that happens, PeerSend sends the funds to the receiver.