Adding to cart variable product impossible

Hi,

From sticky add to cart, I cannot add a variable product to cart. I get the message “Please select some product options before adding this product to your cart”.

I do choose my variation though.
Can you help ?

All my variable products are out of stock for now, you can try on this draft I have made especially for this : https://jolihuit.com/?post_type=product&p=31358&preview=true

Thank you !