How to display an SOS pop-up automatically on just the Homepage

Navigate to the SOS layout that you would like to display automatically on your homepage and select the Show Automatically checkbox.  

Next add the following CSS to Divi > Theme Options > Custom CSS or to your Child Theme.

/* Display pop-up on just the homepage ~ Superfly */
.divi-sos-active .divi-sos-overlay {
   display: none !important;
}

.home.divi-sos-active .divi-sos-overlay {
   display: block !important;
}

Thanks to Andre Esteves Perrone.