Is the 'try it yourself' feature only for premium users?
At the first html lesson, the try it yourself button is available for me to use as a free user. Now, it gives me a message stating that I need to upgrade to continue. Is it normal?
Yes, although there is a longer method to do that, copy the examples/code snippet then experiment in code playground but those are incomplete so you have to complete those snippets or just buy the pro subscription.
"At the first html lesson, the try it yourself button is available for me to use as a free user. " Why is it not available now?
Maybe same problem as mentioned here? https://www.sololearn.com/discuss/2661583/?ref=app
Because that is one of premium features that PRO subscription offers.