None of the existing answers work for me, as WSL2 is running in its own VM and has its own network adapter. You need some sort of bridge or port forwarding for non-localhost requests to work (i.e. from another host on the same network).
I found a script in https://github.com/microsoft/WSL/issues/4150 that worked to resolve the issue:
$remoteport = bash.exe -c "ifconfig eth0 | grep 'inet '"
$found = $remoteport -match '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}';
if( $found ){
$remoteport = $matches[0];
} else{
echo "The Script Exited, the ip address of WSL 2 cannot be found";
exit;
}
#[Ports]
#All the ports you want to forward separated by coma
$ports=@(80,443,10000,3000,5000);
#[Static ip]
#You can change the addr to your ip config to listen to a specific address
$addr="0.0.0.0";
$ports_a = $ports -join ",";
#Remove Firewall Exception Rules
iex "Remove-NetFireWallRule -DisplayName 'WSL 2 Firewall Unlock' ";
#adding Exception Rules for inbound and outbound Rules
iex "New-NetFireWallRule -DisplayName 'WSL 2 Firewall Unlock' -Direction Outbound -LocalPort $ports_a -Action Allow -Protocol TCP";
iex "New-NetFireWallRule -DisplayName 'WSL 2 Firewall Unlock' -Direction Inbound -LocalPort $ports_a -Action Allow -Protocol TCP";
for( $i = 0; $i -lt $ports.length; $i++ ){
$port = $ports[$i];
iex "netsh interface portproxy delete v4tov4 listenport=$port listenaddress=$addr";
iex "netsh interface portproxy add v4tov4 listenport=$port listenaddress=$addr connectport=$port connectaddress=$remoteport";
}
Running this script from an elevated/admin Powershell session did the trick for me. This allows accessing the WSL2 service running on a port to be accessible from the Windows host IP at that same port.