Unable to play two-player games with controller and keyboard

[5vr]

Pi Model or other hardware: 4B
Power Supply used: USB-C 5V 3A Power Supply - Official Power Supply
RetroPie Version Used: retropie-buster-4.8-rpi4_400
Built From: Pre made SD Image on RetroPie website, retropie-buster-4.8-rpi4_400.img.gz
USB Devices connected: Frontech JIL-1731A, YICHIP Wireless Device (Fingers Lil'Clicks)
Controller used: Frontech JIL-1731A
Emulator: lr-fceumm, lr-pcsx-rearmed
Attachment of config files: /opt/retropie/configs/all/retroarch.cfg
How to replicate the problem:

1. First boot > setup Frontech JIL-1731A as gamepad 1
2. Main menu > Configure input > Map keyboard

After doing this, I am able to navigate EmulationStation with both peripherals. However, I am not able to play as player 2 with the keyboard in games such as Super Mario Bros or Mortal Kombat. The player 2 character responds neither to the keyboard nor the controller.

I have followed the following:

• https://www.reddit.com/r/RetroPie/comments/62g3k6/comment/dfma2ud
• https://retropie.org.uk/forum/topic/21002/2-player-support-with-usb-gamepad-and-keyboard

and this happens to me as well - https://retropie.org.uk/forum/post/177119

[mitu]

By default, configuring the keyboard from EmulationStation will configure it as P1, if you wish to make the keybord work as P2, then you'll need to manually modify the retroarch.cfg configuration file for RetroArch and replace the player # in the bindings, i.e.

input_player1_a="X"
input_player1_b="Y"
...
#etc

with

input_player2_a="X"
input_player2_b="Y"
# and so forth