Hardware Need to running personal 4g mobile proxy with 1 dongle for pc ? Quick question!!!

Tò Linux mini-PCs Is connected cellular USB stick with 4gmobile data sim

Hardware setup

3xTL-MR3020 from tp-link
(It support CDC Ethernet-Over-USB )

3x iPhone 7

3x linux pc.
PC with Intel CPU that supports AES-NI .

3x Huawei E3372h +sim

1modem for home wifi

I use 3proxy on my PC tò generate 4gmobile

Should I directly connect my iPhone to the TP-Link modem via ethernet-usb?

Do I need another modem to manage the proxy?

On Reddit, someone suggested buying the RB2011UiAS-HnD-IN, but I didn't u
nderstand its purpose.

I don't want use proxy outside lan

why posting similar threads so often?