can I operate file by a share url

[joyongzhu]

I have read the nextcloud-API ，but I can't find any API to upload or
download by a share url.

I can use the API to read a file/folder, and it need user info (password, username)

nextcloud.NextCloud(url, username, password, to_js)  

but I need some api to read a file by share API becouse i haven't username or password.