How to make email address mandatory

Hi,

There are certain fields mandatory to fill in on the billing address section for the customer. How can I change that? How can I make the e-mail address also to a mandatory field?

I`m using Contao 2.9.3 and isotope 0.2.11

Thanks

I'm not shure if this setting exists in such an old version of Isotope - are you sure that you are using a development version which ist outdated for more than two and a half years?

In the version for productive environments (starting with 1.3.0) you may find the desired setting in the basic shop configuration section.