Most editors format and highlight markdown syntax as bold, italic or strike through, but I have never seen the same thing for html. They only highlight the html-specific parts leaving the content unstyled.
If you want to try a model quickly, you'll have to pay the original provider at least 5 USD. With OpenRouter, you can pay pennies. If you decide it's not for you, then you don't have to leave the rest of your deposit with the provider.