Hi, I am Chinese.
You Can use Baidu Cloud. (just can use Baidu...*sigh*)
You first have to register for Baidu account and Create a Baidu APP. You Can Get Access Token
-> 使用百度授权前准备
Sorry, I did not find the English documentation.
It may be difficult because the Cloud storage service has a special environment in China. In recent years, most disk services have been removed. Only Baidu Cloud is relatively stable. (It seems that only Baidu open the API )
But check it: Baidu API
获取文件列表: Get storage File list
上传文件: Update File
By the way, you can also find similar code on github.
like: baidupcsapi or: bpcs_uploader