Is it necessary to pronounce the letter "Baa" (ب) from the throat, or is it permissible to pronounce it from the lips in prayer?

The point of articulation (makhraj) for the letter 'Bāʾ' (ب) inside and outside of prayer is between the two lips, where they come together when pronouncing it. It is one of the labial letters. As for the larynx, it has no role in the pronunciation of 'Bāʾ' other than being a passage for breath and a pathway for sounds.