How do i configure my orbi router as an access point with the at&t router?

To configure my orbi router as an access point with the at&t router,first we need to connect ORBI router with AT&T router using an ethernet cable into the internet port of the router.Open 192.168.1.1 on the browser ,on the computer that's connected with ORBI network, enter the credentials (user name is admin and password is password).After you are logged in goto advanced > advanced setup > Router AP mode. Select AP mode and click on apply.Your settings are saved for the router.

Connect a ethernet cable with the the orbi router and  the at&t router. Open the browser and the the top long bar type 192.168.1.1, it will open the login window

type the username and the password. (the username  and the password is admin)

Select the advance>advance setup>router/AP mode.

select AP mode, click apply

• Connect an Ethernet cable to the Internet port of your Orbi router and to the LAN port of your At&T Router.
• Launch a web browser from a computer or mobile device that is connected to the Orbi network and enter http://orbilogin.com or 192.168.1.1
  The login window opens.
• Enter the router user name and password(default username is admin and password is the password)
  Once you are logged in, then
• Select ADVANCED > Advanced Setup > Router/AP Mode.
• Select AP Mode.
• Click Apply.
  Your settings are saved.