Pronunciation is wrong (for it to be Classical Latin, as hinted to by the flag). Further, there should be macrons for long vowels, such as for Stephānus. Lastly, ‘I am Stephen’ should be accepted, as it is the English variant if that Latin name. After all, it could be argued his name was Stephān, -us merely indicating nominative, as can be seen in numerous posters from the time, the case ending being omitted for brevity.
Edit: I later learned that the name was in fact Stephanus, not Stephānus.