Adding intro text to Woocommerce Shop Page (2)

In an earlier support thread with the same title, Adding intro text to Woocommerce Shop Page, now closed to replies, you gave this advice: “Open the Shop page, then add your description in Excerpt box, then choose Display page excerpt as header cover description in Page Settings box”.

Is the Page Settings box specific to OneTheme? My WordPress installation doesn’t have it, unless there’s some hidden setting to enable it, so I can’t follow your instruction. I am using my own theme (a child of Twenty Seventeen), not OneTheme, so I hope you’ll forgive my posting here.

I’d be very grateful for any help in getting or enabling the Page Settings box. Is there a plugin, perhaps? Unfortunately I can’t switch to OneTheme as my project is too far advanced for that.

Phil