Hi, like to share my experience.

I signed up for Time 500Mbps plan, which comes with 2x Huawei 8145X6-10 routers. The Time installer set up 1x as a 2-in-1 (Modem + Router), and another 1x with Mesh.
I already had my own TP-Link AX73 with Unifi, and I decided to use the Huawei 8145X6-10 as a modem only.

I called Time helpline, and the technical team called back within 2 hours.
Apparently it can set it physically with it, the settings (as a modem only) needed to be adjusted on Time end to switch from 2-in-1 to modem only.
At my AX73, I need to made sure the LAN cable was connected from Huawei 8145X6-10 (LAN1) to the AX73 WAN port. And AX73 set with PPPoE method with the login credentials provided by Time. It worked. Hope this helps~ 

This is how i do it

Time modem HG8145X6
Tplink router AX73

step 1: call TIME cs ask to change to bridge mode
step 2: go to modem admin panel, disable wifi
step 3: connect LAN1 modem to WAN port router
step 4: inside router admin panel, change connection type to pppoe and insert your time user:pass credential

done

VLAN is not needed for TIME after using bridge mode.

Are you sure your ONT is in bridge mode? You should have no internet when it’s in bridge mode.
I assume the username and pass is obtained from TIME selfcare.

Nobody here had ever gotten access that's why. Can you tell us the username and password?