What is the supplication that protects one from fire?

There is no authentic, specific supplication in the Sunnah that protects a Muslim from fire. However, the Prophet, peace and blessings be upon him, used to seek refuge from fire and from calamities in general, as mentioned in the hadith of Abu Al-Yasar, may Allah be pleased with him. There are weak hadiths regarding supplications for protection from fire, including the hadith of Abu Darda, which was deemed weak by Ibn al-Jawzi and others. As for when a fire occurs, it is recommended to say "Allahu Akbar" (Allah is the Greatest) to extinguish it. A weak hadith from Abdullah ibn Amr ibn al-Aas mentions this. Ibn Taymiyyah and Ibn al-Qayyim explained that saying "Allahu Akbar" repels the devil who aids in the spread of fire, and that nothing can withstand the greatness of Allah, thus the fire is extinguished.