In the Page Settings panel, there is a group of fields labelled "Facebook Tags." Note: this is only available within Shopify.
These fields populate the page's OpenGraph meta tags, such as og:title and og:image. OpenGraph tags control the content that is displayed in feeds whenever your page is shared on Facebook.
The Type field is used to assign a category to the page, such as a product or article.
The Title, Image, and Description are what is displayed in people's Facebook feeds when the page's URL is shared.
The App ID is an optional field when it comes to sharing pages. It can be useful if you have a Facebook application affiliated with your business, but it is not required.
Why doesn't the info I see on Facebook match what I've added?
Facebook caches page information for at least 24 hours, so changes made to these fields will not be immediately reflected when pages are shared. The wait time can be expedited by using Facebook's Sharing Debugger tool: https://developers.facebook.com/tools/debug/sharing/
Simply paste in the URL of your page and click the "Scrape Again" button to trigger Facebook to pull in the page's latest data. Once this has been done, the correct data should appear in the tool and on all page shares moving forward.