I’m not sure, which wordpress version you are using but all wordpress versions supports custom html embedding on page.
Here’s how you can do: (WordPress 5.1.1)
- Go to Pages
- Add/Edit Page
- Click on Plus Icon (step 1 in below screenshot)
- Search for Custom HTML (step 2 in below screenshot)
5. Paste map html in page (sample available below)
Keep in mind, adding custom css and javascript; directly in page is not recommended!
Hope it helps! 🙂