Which API should the master send the passkey to the slave?

[xiaolei]

I need to do pairing between the two 51822 modules. All the information I find is paired with the slave and the mobile phone. There is no host matching process demo or learning materials?
Nothing to start with. . Hurry

Which API does the host need to call and which event is triggered?

[haakonsh]

See the Heart Rate Application example and BLE Heart Rate Collector Example.