How to set subfolder from s3 bucket as root folder in file manager

I’m using s3 bucket for file manager, i have different projects and for each of them i need to create their own folder for files and set it as root folder for file manager, how can i do that?

I did that on backend, but i want to know if i can set custom params to query, currently i do like that:
webix.attachEvent(‘onBeforeAjax’, (headers) => {
headers[‘Project-Id’] = projectId;
but i want to know if i can do something like that:

yes, sure, you can change the way requests are sent by extending the Backend service and overriding its methods. Code Snippet
For more details, please see Working with Server of UI Complex Widgets, File Manager Webix Docs