I do not know how to correctly put it, but the point is that there is a server with configured Asterisk.
There are 5 sites, new sites will be added. On these sites there are buttons to "Call me back". Now all configurations, written by hand.
It is necessary to make the possibility of registering new sites. When you register you need to automate the addition to the configuration of Asterisk, as each site can have its own operator.
My stupid idea:
1) Open extensions_custom.conf
2) Add to the end of the parameters (site/operator)
3) Run the command asterisk-r > reboot