Why won't Wcart let me use a word like cart or account as a URL prefix?

Some words are blocked because a built-in store page already uses them.

On Settings → SEO Settings → Permalink, every prefix must:

• Use only lowercase letters, numbers and hyphens, like new-arrivals.
• Not be a reserved word such as cart, checkout, account, search, wishlist, compare, quote, login, signup or admin. Otherwise it would hide that page.
• Be different from every other prefix on the page.
• Not be empty. Only the Page prefix may be left blank.

Pick another word, for example store or collections, then click Save and Approve & apply.