You will receive a call from IRCC (no caller id/unknown no) for biometric appointment, they will ask some basic info and book you for nearest SC location/SC passport center with earliest/suitable date & time slot. You won't receive any confirmation email or details, its your responsibility to note down slot time and SC center address. You just have to be present there on given slot time by following instruction given on call. At the SC center, they may ask COVID related questions randomly to anyone (didn't ask in my case), your appointment detail such as app number and time slot then allow you to give biometric. It hardly takes 10-15 mins at center to complete the biometric process.