Hello friend!
In the case of PPPoE dial-up accounts of the two model ONTs, you need to log in to the WebUI of the device using the device administrator account to configure the PPPoE dial-up accounts. The procedure is as follows:
Note that the administrator account of the device is usually used by engineers for onsite maintenance. We cannot know the administrator account and password of the device. To obtain the administrator account and password of the device, contact the device provider or ISP.
EG8145V5
In the navigation tree on the left, choose Advanced > WAN. In the pane on the right, click New:

HG8546M
In the navigation tree on the left, choose WAN > WAN Configuration. In the pane on the right, click New:

Thanks!