GET https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=APPID&secret=APPSECRET

    var that = this
    let APPID = "xxx"
    let APPSECRET = "xxx"
    wx.request({
      url: `https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=${APPID}&secret=${APPSECRET}`,
      method: 'GET',
      success: (res) =>{
        console.log(res)
        console.log(res.data.access_token)
        that.setData({
          access_token: res.data.access_token
        })
      },
      fail: (res) =>{
        console.log(res)
      },
    })

POST https://api.weixin.qq.com/cv/img/superresolution?img_url=ENCODE_URL&access_token=ACCESS_TOCKEN

      wx.request({
        url: "https://api.weixin.qq.com/cv/img/superresolution",
        data: {
          img_url: "https://gss3.bdstatic.com/-Po3dSag_xI4khGkpoWK1HF6hhy/baike/c0%3Dbaike116%2C5%2C5%2C116%2C38/sign=8816325c4036acaf4ded9eae1db0e675/fcfaaf51f3deb48fcfadd0bbfb1f3a292cf5788a.jpg",
          access_token: that.data.access_token,
        },
        method: 'POST',
        dataType: "json",
        header: {
          'content-type': 'application/x-www-form-urlencoded'
        },
        success: (res) => {
          console.log(res)
          that.setData({
            media_id: res.data.media_id
          })
        },
        fail: (res) => {
          console.log(res)
        },
      })

curl "https://api.weixin.qq.com/cgi-bin/media/get?access_token=ACCESS_TOKEN&media_id=MEDIA_ID" -o "output.jpg"

    setTimeout(function () {
      var downloadUrl = `https://api.weixin.qq.com/cgi-bin/media/get?access_token=${that.data.access_token}&media_id=${that.data.media_id}`
      console.log(downloadUrl)
      that.setData({
        downloadUrl: downloadUrl
      })
    }, 2000)

<view class="section">
  <view>图片URL: </view>
  <textarea maxlength="1000" bindblur="bindTextAreaBlur" auto-height placeholder="请输入图片链接" />
</view>

  bindTextAreaBlur: function (e) {
    console.log(e.detail.value)
    this.setData({
      imgUrl: e.detail.value
    })
  },