1) Very first and classic way to embed any site is using iframe tag.
<iframe width="100" height="100" src="https://www.your-domain.com/"></iframe>
In this classic method, all you need to do is define the height, width, and source to embed any URL.

2) Another way to embed website is using oEmbed tag
<embed height="560" width="315" src="https://your-domain.com/" />
With OEmbed tag, you can even style the container with CSS. It also doesn’t require a closing tag and all major browsers support it.
Which is one of faster and easier way to embed content into WordPress.

Hopefully, it works for you.
Good luck.