“please choose a date” problem easy booking

Hi, I have a problem when trying to assign bookable calendar to product, apparently the calendar appears correctly and select the date, but when a user click on “add to cart” an error appears saying “please choose a date”. I don’t use any cash plugin in my website. and i use a wordpress hosting from Namecheap.
this is the link to my website
https://doriadress.fr/

thank you for your help
best regards

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