This was close to working for me. Also had to add

"changeOrigin": true,
"pathRewrite": {"^/proxy" : ""}

full proxy.conf.json shown below:

{
  "/proxy/*": {
  "target": "https://url.com",
  "secure": false,
  "changeOrigin": true,
  "logLevel": "debug",
  "pathRewrite": {"^/proxy" : ""}
  }
}

This was close to working for me. Also had to add:

"changeOrigin": true,
"pathRewrite": {"^/proxy" : ""}

Full proxy.conf.json shown below:

{
    "/proxy/*": {
        "target": "https://url.com",
        "secure": false,
        "changeOrigin": true,
        "logLevel": "debug",
        "pathRewrite": {
            "^/proxy": ""
        }
    }
}