No, it's not what they want. If they wanted you to use a LLM then they would tell you that up front. It's also too new of a technology to be required anywhere. Hardly anyone I know is even trying LLMs to begin with. Then, what do you do if the interviewee gets garbage code out of the LLM and misses an error? An error that might be forgiven in a normal interview cannot be excused when you didn't even have to write the code. Technically, if the LLM did the coding for you, you might pass without even being able to read code. This is all like the same reason you can't use a laptop on an algebra exam... The tool might do 100% of the work and leave you having shown nothing of your own ability.