Nextcloud Webdev API - Sabre Dev

we are trying to download , upload Nextcloud files via sabre webdev in PHP.
Currently we are able to run “profind” webdev command and we are getting properties of files from Nextcloud root folder successfully but when we try to use put or get command then we get below response.

PSB Screenshot:

Are we missing any nextcloud app configurations or is there we could dig down further in our API.
We will appreciate the prompt response.
Thanks in Advance.