USB Fast Charging 9V/2A: LG Charger & Device Recognition for Higher Voltage Support

Hello. Recently, I have been wondering about the charging speeds of devices with a USB socket. The topic of 5V / 2A charging instead of the standard 5V / 1A is already well-rolled on the electrode and it is clear to me, but I am wondering about the principle of 9V / 2A fast charging. By default, my LG stupidphone charger has 5V, when charging most devices, this voltage is maintained, while after connecting the mentioned LG, the voltage increases to 9V. Does anyone know how the charger recognizes a device that supports the 9V / 2A standard? Is this some sort of message on the USB or something like that?

You are interested in the issue of Power Delivery. Enter the exact model of your phone and charger.
The USB-C standard, for example, has additional communication lines through which the receiver informs the energy supplier (power supply) about its power plan.

Another matter may be due to the fact that LG's Quick Charge technology is on Qualcomm's lists.
An example of a solution to this problem:
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The thing here is that on the D- and D + data lines, the charger and the phone communicate to establish a power plan.

Hmm, I understand, so it's not a question of "solder the resistor and it will go". Thanks for the answer, the NCP4371 chip is what I was looking for. From what I can see, you can get it for PLN 3.