iframe not working

Question

Why is my iframe not working?
https://code.sololearn.com/W8cegnabc9Co/?ref=app

Answer 1

Try to get its embedded url
https://www.sololearn.com/learn/338/?ref=app

Answer 2

Read this https://www.w3schools.com/html/html_youtube.asp

Answer 3

Thank you now I get it =)