Yealink SIP VP-T49G User Manual page 263

To configure the shared line settings and the number of line key on phone A via web user
interface:
Register the primary account 4603.
1.
Click on Advanced, and then select Share Call Appearance from the pull-down list of
2.
Shared Line.
Enter the desired number in the Number of line key field.
3.
This field appears only if Auto Linekeys feature is enabled.
Advanced Phone Features
263