Trezor Hot wallet API


I am looking to develop my own crypto payment gateway with Trezor. My question is basically that I am being told that I would be able to access Trezor hot wallet API so thus creating multiple sub wallet address of one master wallet via API without having Trezor device connected with the computer.

Can anyone do elaborate on this ?

From my understanding, i thought i would must connect Trezor device with my computer