Set date of birth to mandatory

[Pollklesener]

Hi all,

 

we're currently setting up our PrestaShop page and have a payment plugin which requires the date of birth as confirmation for the credit card details.

I found the option at "Shop parameters > Customer settings", so the date of birth is now shown in the payment process. But it is actually just optional.

 

How can this be set to mandatory?

 

Thanks in advance for your help.

 

Kind regards

Christian