You don't need an adapter,assuming your phone is actually a dual SIM model, the second slot is shaped so that it will hold either a micro-SD card or a nano SIM .
Try something like this on Amazon
2 Pcs SIM Card Adapter Kit - 4 in 1 Nano Micro Standard Converter Kit with Steel Tray Eject Pin 1 https://a.co/d/1YhZ1TS