Question: How do I pair devices with security code?

[Aukstkalnis]

Hello. I am trying to find out how to pair to a central device that requires a pairing key. I could not find any info in the examples. Should I use another library for this purpose? Or should I directly interact with bluetoochctl (a.k.a bluez)?

Use case:
I am writhing application that connects to device, makes some configuration and disconnects. So, there will be a lot of devices and each has its own pairing code.