Found a solution!
https://debianforum.de/forum/viewtopic.php?p=1358882#p1358665
Install all Pipewire packages
Create this file:
~/.config/pipewire/pipewire.conf.d/swapped_channels.conf
and paste this:
context.modules = [
{ name = libpipewire-module-loopback
args = {
audio.position = [ FL FR ]
capture.props = {
media.class = Audio/Sink
node.name = swapped_channels
node.description = "Switched Channels"
}
playback.props = {
node.name = swapped_channels
node.description = "my-sink"
audio.position = [ FR FL ]
node.target = "Switched Channels"
}
}
}
]
Then Choose pulseaudio in strawberry in and Choose this device: Switched Channels