Angular 11 proxy not proxing

Question

I have this current configuration in the proxy.conf file

{
  "/mgr/admin/api/*": {
    "target": "http://actual-target.com/",
    "secure": true,
    "changeOrigin": true,
    "logLevel": "debug"
  }
}

I need to have the mgr part parametric as well since it can be mgr-hash or stay just mgr.

I tried to add a regex in order to fit the possible mgr values like following, but without any luck

{
  "/mgr[A-Za-z0-9-]*/admin/api/*": {
    "target": "http://actual-target.com/",
    "secure": true,
    "changeOrigin": true,
    "logLevel": "debug"
  }
}

In the first case it is proxing but in the second one it isn't. Any hint? I am calling /mgr/admin/api/login url. why in the second configuration it is not proxing? Thanks in advance