This is the simplest client for users of Apple products. You can download it from the link.
In the "Full Name" field, enter the name of the employee that will be displayed in the application
In the "Domain" field, enter the IP address of the MikoPBX to which the connection is being made
In the "User Name" field, enter the internal number of the employee
In the "Password" field, enter "SIP password"
Click "Done"
The green indicator on the top indicates successful authorization. Also, the status Online should be displayed on the PBX for this internal number.