Trouble Increasing TXpower in Kali 2020.3

I have two wireless cards ...i want to change country regulations to increase db , But i am not able to set my second card .

Commands used
iwconfig wlan0 down
iwconfig wlan1 down
iw reg get
iw reg set BO
puts only one card to BO (wlan0) regulation



Secondly

Not able to increase TXPOWER even after putting one card to B0
Commands used
iw dev wlan0 set txpower fixed 30
also tried
iwconfig wlan0 txpower 30
getting error
operation not supported (-95)

Note :- iw list still shows only 16db power even after putting card in BO regulation

using latest kali 2020.3 up to date drivers etc