To fix typos in your code, place the cursor anywhere on the misspelled word and hit Alt+Enter to invoke the intention actions dialogue then select Typo: Rename to... .
PhpStorm will either prompt you with a popup containing a text field to provide the correct spelling for the word, or an autocomplete list with suggestions for alternative spellings for you to choose from. If you don't like anything from the autocomplete list you can start typing to provide your own spelling for the word.
It's best to leverage PhpStorm when fixing typos because it will rename every usage of the symbol (variable, method, class, etc.) throughout your codebase, doing all of the heavy lifting.