Error Messages:
Access to XMLHttpRequest at ‘http://www.localtest.com/api/api/v1/job/getPositionList’ from origin ‘http://localhost:8080’ has been blocked by CORS policy: Request header field os-version is not allowed by Access-Control-Allow-Headers in preflight response.

Original request interface

http://www.localtest.com/api/api/v1/job/getPositionList

Solution:

Configure cross-domain in the manifest.json file, the method is similar to devServer in vue.config.js

"h5" : {
        "devServer" : {
            "disableHostCheck" : true, // Enable you to use your own domain name 
            "proxy": {
              "/api": {
                "target": "http://www.localtest.com",
                "changeOrigin" : true,
                "secure" : false,
                "pathRewrite": { //api in the matching request path will be replaced with https: // www.test.com
                // Example: /api/api/user => https://www.localtest.com/api/user
                  "^/api": ""
                }
              }
            }
        }
    }

in addition

baseUrl = process.env.NODE_ENV === 'development' ?'/api' : 'https://www.localtest.com' 
Then the url requested by uni.request should be like this: 
baseUrl + '/user/info' 
then The request address seen by the browser should be http: http://localhost:8080/user/info