With the Charge theme, you can turn on the cookie consent banner on Shopify.
Note: To show the cookie banner that is available for EU visitors, you have to select the option “Collected after consent” located in the Shopify admin - Online Store - Preferences - Customer Privacy.
Go to Online Store - Theme Settings - Cookie banner to customize the banner. Here you can put a checkbox in the Show cookie banner field. You can also specify a cookie banner title, change the days for compliance consent cookies to expire, and show a link to the cookie privacy page. And with the Charge theme 1.6.0 release, you can decline the cookies.