How can I make a read more and read less button?

Question

I got issues from Mitali's video in YouTube:

If you click the button the third time it doesn't work.
It only shows "Read Less" if you click it.
It doesn't change its text in the button.

That's why I made this instead.
https://code.sololearn.com/W52THRu8npSc/?ref=app

Answer 1

https://www.w3schools.com/howto/howto_js_read_more.asp

Answer 2

Still not correct. The button is not shown