In Google Maps, after you find your location, click Share, then the Embed a Map tab, and copy the HTML.
Once you're in Libretexts and editing your page, in the top menu click View, and then Source, and paste the map's HTML where you want it.
Click View and Source again, and your map should be there on the page.
(If you really don't want to work with the page source, you can cheat instead - in the top menu click Elements, then Video. Click the Embed tab, paste in the HTML you copied from Google Maps, and click Insert Video. It will insert your map there.)