First you must make sure your Repl is public.
Then you can copy the URL and append "?lite=true". Note you must get rid of any text after the #, and not have any # characters.
https://repl.it/@TimothyClark/Dice-Bag?lite=true
And then embed that link as you would any other google site embedding:
If you would like to embed just the program running without the code, append: "?lite=true&outputonly=1"
https://repl.it/@TimothyClark/Dice-Bag?lite=true&outputonly=1