Crawl the APP with a packet capture tool

Configuration Environment

Install filddler according to this. Then you can observe all url requests accessed by your computer and mobile phone. 
https://jingyan.baidu.com/article/3a2f7c2e0d5f2126aed61175.html?qq-pf-to=pcqq.c2c

filter url

https://www.cnblogs.com/yoyoketang/p/6582437.html 
According to this setting, you can only choose to watch the url request of the app. 
Then you can crawl.