DidYouMean is a component used to suggest a possible misspelling correction to the current query.

Add the did-you-mean block to the search-result-layout.desktop or search-result-layout.mobile. For example:

"search-result-layout.desktop": {
    "children": [
        "flex-layout.row#didyoumean",
    ],
    "flex-layout.row#didyoumean": {
        "children": ["did-you-mean"]
    }
}

In order to apply CSS customizations in this and other blocks, follow the instructions given in the recipe on Using CSS Handles for store customization.