Rendering problem of pongo2 template for golang

type UserInfo struct {
    UserId              int    `json:"user_id"`
    Nickname            string `json:"nickname"`
}

func (data UserInfo) A() int{
    return 1
}
func (data *UserInfo) B() int{
    return 2
}

...

c.HTML(http.StatusOK, "test.html", pongo2.Context{
        "user_info": userinfo,
        "user_infos": &userinfo,
    })
<div>{{user_info.A()}}</div>  //1
<div>{{user_info.B()}}</div> //
<div>{{user_infos.A()}}</div>  //1
<div>{{user_infos.B()}}</div> //2

Why is user_info.B () empty?

Sep.23,2021
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