PostForm之后的301状态代码

I am trying to write a program which will login to ahrefs.com and parse some data. At first I am sending GET request to ahrefs.com to get cookies and html to parse needed token:

    client := &http.Client{}
    jar := &myjar{}
    jar.jar = make(map[string] []*http.Cookie)
    client.Jar = jar
    resp, _ := client.Get("https://ahrefs.com")

    root, _ := html.Parse(resp.Body)
    element, _ := getElementByName("_token", root)
    token := ""
    for _, a := range element.Attr {
        if a.Key == "value" {
            token = a.Val
        }
    }

Then I am sending POST request using PostForm to ahrefs.com/user/login/. I fill the fields with correct data (tested it via browser). When I submit form in browser it has field return_to with value of main page of the site, which should redirect to ahrefs.com/dashboard/metrics/ (the page from I want to parse data). But my program's behavior is different. After PostForm I got 301 status code:

resp, _ = client.PostForm(
        "https://ahrefs.com/user/login/",
        url.Values{
            "email": {"djviman@gmail.com"},
            "password": {"Aau4bqRxfc4ZEvu"},
            "_token": {token},
            "return_to": {"https://ahrefs.com/"},
        })
    log.Println(resp.Status)
    resp.Body.Close()

Then I am sending GET request to ahrefs.com/dashboard/metrics/ but it redirects me to the home page, like I'm not logged in:

resp, _ = client.Get("https://ahrefs.com/")
    log.Println(resp.Status)
    resp.Body.Close()

Questions are: what I am doing wrong? And hot to successfully log in to this site?