Answer:
Satan is of the jinn. He was never of the angels. There are Jinns who are believers and others are unbelievers.
(And ˹remember˺ when We said to the angels, “Prostrate before Adam,” so they all did—but not Iblîs,1 who was one of the jinn, but he rebelled against the command of his Lord. Would you then take him and his descendants as patrons instead of Me, although they are your enemy? What an evil alternative for the wrongdoers ˹to choose˺!) Al-Kahf 18:50
إبليس من الجن . الجن منهم الصالحون و منهم الكافرون
) وَإِذْ قُلْنَا لِلْمَلَائِكَةِ اسْجُدُوا لِآدَمَ فَسَجَدُوا إِلَّا إِبْلِيسَ كَانَ مِنَ الْجِنِّ فَفَسَقَ عَنْ أَمْرِ رَبِّهِ أَفَتَتَّخِذُونَهُ وَذُرِّيَّتَهُ أَوْلِيَاءَ مِن دُونِي وَهُمْ لَكُمْ عَدُوٌّ بِئْسَ لِلظَّالِمِينَ بَدَلًا﴿
الكهف 18: 50﴾