将编码的字符串添加到http共振似乎将某些字符替换为！F（MISSING）。如何预防？

输出：

{“ encodedText”：“ M6c8RqL61nMFy％！F（MISSING）hQmciSYrh9ZXgVFVjO”}

码：

package main

import (
    "encoding/json"
    "fmt"
    "net/http"
    "net/url"
)

type EncodeResult struct {
    EncodedText string `json:"encodedText"`
}

func main() {

    http.HandleFunc("/encodedString", encodedString)
    _ = http.ListenAndServe(":8080", nil)
}

func encodedString(w http.ResponseWriter, r *http.Request) {

    inputString := "M6c8RqL61nMFy/hQmciSYrh9ZXgVFVjO"
    er := EncodeResult{url.QueryEscape(inputString)}
    response, _ := json.Marshal(er)

    w.Header().Set("Content-Type", "application/json")
    fmt.Fprintf(w, string(response))
}