The Chinese translation is 真言; zhenyan; 'correct phrases', the Japanese on'yomi reading through with the Chinese staying shingon (that's also applied as the correct identify to the Shingon sect). His mantra is "Ǎn hōng zhā lì sà mó luō - 唵吽吒唎薩嚩囉". Taoist feel this incantation to be the center https://www.youtube.com/watch?v=ebjMeUz17Ro