When registering a recipient to the contacts list, you can select IP-FAX(IP-LAN) as the line setting.
On a computer connected to the same network as the printer, open a browser and enter the printer's IP address.
You can check the printer's IP address using the following menu.
Enter the administrator password to log in as an administrator.
Select the following menu.
Scan/Copy tab or the Fax tab > Contacts
Select the number that you want to register, and then click Edit.
Enter the Name and Index Word.

Select Type for the Fax.
You cannot change the Type option after registration is complete. If you want to change the type, delete the destination and then register it.
Select IP-LAN in Select Line.
Enter the destination in SIP URI
Select other settings as necessary, and then click Apply.