How to properly process incoming calls from a sip operator to several numbers?

Question

Asterisk

Please tell me, if you set up a sip connection in asterisk for incoming calls from the operator with one extension [sipoperator], and if 3 virtual numbers are purchased, register them in the dialplan for processing incoming calls, will it not be busy if they call all three at the same time? for each virtual number from the operator, do you need to make your own extension or just one connection and process at least 10 numbers in dialplan? Thank you