Enabling monitor mode for Raspberrypi fails with error: ERROR adding monitor mode interface: command failed: Operation not supported (-95)

Question

Im trying to create a evil twin on my own network. I followed some tutorials how to create one. My raspberrypi is controlled by SSH via lan but i found a Wlan usb stick that is now plugged in but doesnt work. I googled why and on certain platforms they said I needed a driver.

Im using airmon-ng Procedure:

hops@networker:~ $ sudo ifconfig wlan0 down
hops@networker:~ $ sudo airmon-ng check kill

    Killing these processes:

    PID Name
    407 wpa_supplicant
    511 wpa_supplicant
    597 dhcpcd

hops@networker:~ $ sudo airmon-ng start wlan0

Found 2 processes that could cause trouble.
Kill them using 'airmon-ng check kill' before putting
the card in monitor mode, they will interfere by changing channels
and sometimes putting the interface back in managed mode

    PID Name
    857 wpa_supplicant
    880 dhcpcd

PHY     Interface       Driver          Chipset

phy0    wlan0           brcmfmac        Broadcom 43430

ERROR adding monitor mode interface: command failed: Operation not supported (-95)

1. I don't know what exactly I'm doing wrong why this happens.
2. Why I can't kill the other processes that are still running

My Wlan-usb: TP-Link Archer T3U OS: Rasbian Os 64-Bit lite

Thanks for your answer :)