DELETE and PUT commands do not work, why?

In order to use QuickBlox API you need to create session. After this you will have READ access to the QuickBlox environment.

In order to CREATE/UPDATE/DELETE records you must be logged in and act on user’s behalf.

There are two ways for this:
-  Create session with user’s parameters https://docs.quickblox.com/reference/authentication#create-session
-  Create session and then sign in https://docs.quickblox.com/reference/authentication#log-in

Please keep in mind that you will be able to delete your own object, not other users object.