Install 3cx in windows or linux, While installation IP should be static and cannot be changed,
Once changed you have to take backup, reinstall 3cx with new IP and restore the backup.
Changing the IP’s affect extension provisioning, wallboard and Reporting,etc….
If you enable “PBX Deliveres audio”, “SIP Replace header” and “Supports Re-Invite” in extension
settings, You should enable it in SIP Trunk Settings.
SIP Trunking configuration
Read more at : https://www.htsqatar.com/3cx-trunking-yeastar-pbax/