minimum order

-- url of the page with the problem -- : kebab24.webserwer.pl/ct-menu-item-3/ct-menu-item-7

Hello . Where to set the options. The minimum value of the contract , for instance 20 euros. Please, detailed description

Hi,

You can for example edit all your payment methods via the menu System>Payment methods and set the "minimum price" restriction setting of each one to 20 so that they would display only for orders with a total amount above that.
And thus the system won't let the customers checkout if no payment methods are available, and you can then customize the error message displayed in such cases with a translation override:
hikashop.com/download/languages.html#modify