@Paul ********
All I’m saying is that on my British passport, the ‘Authority’ field states HMPO, and that’s exactly what the embassy staff instructed me to enter. I followed their guidance, and my visa was approved without any issues.
Before that, I had asked several people and received conflicting advice—some said to enter United Kingdom, while others said HMPO. That uncertainty is why I decided to go directly to the embassy to confirm the correct answer. I didn’t want to take any chances.