Question about Basilique cathédrale Saint-Denis Paris
 

I'm wondering if anyone has information about how to get a ticket here. When I click on the "ticketing" I see an option for "Visit for the Monument" When I click on it I see this: (please continue to read below.) Im confused by the sentence with italics, but there is no place to pick a date. The next page is "Checkout." (See more below)
► Attention : this ticket alone does not allow entry.11,00 €

Donation
Donation : I support la basilique de St Denis2,00 €

Audioguide
Audioguide3,00 €
The next option is: The Basilica of Saint-Denis
Discover with a tour guide the Cathedral Basilica of Saint-Denis. In this option I can pick a date and time - but the entire month of October is grayed out. I desperately want to go, can anyone help me? Thanks! Susan

The basilique de Saint Denis is so empty that you do not need an advance ticket. It is a kindness to buy your ticket when you arrive because the ticket booth attendants must get so bored that they are happy to see a visitor.

Thank you so much for this, Kerouac. Much appreciated. :)