You cant do that in sololearn neither on the internet. A person can see ur code on internet by inspecting the page. theres no way of hiding your code. tho ur question is still kinda unclear, What do you mean by "page code"?
There is no way to hide your source code. Even if you hide the page in an iframe, if it can be viewed in a browser it can be pulled from the internet with tools such as wget, or a simple python script.
If you don't want people to see it, don't put it on the internet.
Make it private ! It's simple ..
There are two ways to do so
While saving you get the option of making it public or private
After posting it you need to go to your code and their select options there only you will get the option to make it private!!
Hope it helped you
You need to have your own web development language which actually no one can understand.
Example like this:
Ohhh yeahhh boy ;)