The standard way of spelling entitled is with an “e”; intitled is an archaic (outdated) spelling.
On a similar note, if you can’t decide whether entitled or titled is correct for stating the title of a movie, book etc. (e.g., “The painting is titled/entitled Blue”), you can use either word because both are correct (although many style guides recommend using “titled” for this meaning).
A QuillBot Grammar Check will help you pick up spelling errors such as “intitled.”