JavaScript find string and highlight

I’m having some issues with searching a string in long text. I want to extract only searched text and highlight searched text with maybe 10-20 characters before it and after searched characters.

So basically what I want to achieve is, ex. from that text:

Hi there, I want to achieve a new goal to create a good search bar for
my app. It should be just as any other search bar.

So if I want to search “good search”, it should return something like:

…achieve a new goal to create a good search bar for my app. It
should be just…

So I just bolded the text, and took few characters from the left and right.

What would be a best way to do it? I tried something like:

 const text = "Hi there, I want to achieve a new goal to create a good search bar for my app. It should be just as any other search bar."
    const search_text = "good search"
    const radius = 10;
    // To determine where is the first character
    const find_first = text.search(search_text)
    const search_from = find_first - radius;

    // To ensure that we are taking from first with length of searched text and additional ones
    const search_to = find_first + search_text.length + radius

But still, this is only to determine how to check which characters to get. But how to list them and show with highlight?