How do modify the from header domain

Hi team
How do modify the header domain ,

From: “123456789” <sip:123456789@
From: “123456789” <sip:123456789@

Could you explain use case for this? Usually yeti inserts own IP as from domain.

If the domain is a FIXED value, then in the Vendor Gateway’s Signalling Tab, in the Termination section → Term append headers req, you can input:

From: “fU” <sip:fU@>\r\n

I deployed Yeti to the cloud and docked the SIP Trunk
SIP header “from” and “contact” sent to the line are both Intranet IP
I need to change the Intranet IP to the public IP
From: sip:012345678@ ---------From: sip:012345678@PublicIP:5060
Contact: sip:;transport=udp
Contact: sip:PublicIP:5060;transport=udp

it is bad idea to insert mandatory headers like From using Term append headers req feature

you have to use public-address sip interface parameter to define public address

Thank you for your reply
How does this parameter work?
I did not find information about.

Thank you for your advice
Hope to exchange and learn