https://developers.weixin.qq.com/doc/offiaccount/Asset_Management/New_temporary_materials.html

文档中并没有记载 type=thumb 这个情况,属于误导:

{
    "type": "thumb",
    "thumb_media_id": "SfE42Oy3x2SLQzgaXsUuWgl-ZhTFRS5DMWCFLbCmh9RS1gHGSc5-CMMWCWYu7kLN",
    "created_at": 1718691181,
    "item": []
}