Make sure you have gdb installed. For that you can use:

brew install gdb

Then make the gdb binary is certified. Because:

... modern Darwin kernels restrict the capability to assume control over another process (here, for the purpose of debugging it), since that capability is a boon to malware. In order for said taskgated to grant access to gdb, the latter must be fitted with entitlements, which consist of digitally-signed metadata inside the gdb binary.

From: https://sourceware.org/gdb/wiki/PermissionsDarwin

To create a certification follow these instructions: https://sourceware.org/gdb/wiki/PermissionsDarwin

After doing so, certify the binary as instructed here.

Then try this for launch.json:

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
        {
            "name": "g++ - Build and debug active file",
            "type": "cppdbg",
            "request": "launch",
            "program": "${fileDirname}/${fileBasenameNoExtension}",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${fileDirname}",
            "environment": [],
            "externalConsole": false,
            "MIMode": "gdb",
            "preLaunchTask": "C/C++: g++ build active file"
        }
    ]
 }

If you are using WSL to compile the project you should not use MinGW gdb. You need to install gdb on you Linux subsystem (using native tools like apt if you are using Ubuntu WSL), reopen your project in WSL and configure the WSL path to gdb. I was able to successfully debug using this setup on WSL.

Adding this entry to launch.json worked for me

"preAttachCommands": [
     "set substitute-path /path/during/build /path/for/debuging",
],

From https://github.com/Marus/cortex-debug/issues/611#issuecomment-1076250854

In your case, that would be

"version": "0.2.0",
"configurations": 
[
    {
        "type": "gdb",
        "request": "attach",
        "name": "gdbserver",
        "gdbpath": "/usr/bin/gdb",
        "program": "/app/bin/exe",
        "target": "target_ip:port",
        "remote": true,
        "cwd": "/",
        "preAttachCommands": [
            "set substitute-path /path/during/build /path/for/debuging",
        ],
    }
]