417 status code when api is called

Im trying to create a url path for the image im capturing from the camera. while i call the api im getting this status code and error like.

Traceback (most recent call last):
File “/home/kare/frappe-bench/apps/frappe/frappe/handler.py”, line 56, in execute_cmd
method = get_attr(cmd)
File “/home/kare/frappe-bench/apps/frappe/frappe/handler.py”, line 189, in get_attr
method = frappe.get_attr(cmd)
File “/home/kare/frappe-bench/apps/frappe/frappe/init.py”, line 1199, in get_attr
return getattr(get_module(modulename), methodname)
AttributeError: module ‘kare_dev.kare_dev.doctype.child_master.child_master’ has no attribute ‘create_image_url’.

But the module does exist and the method to. testing in the local systems is working fine but in dev instance(version 13) in the server im getting this error tested in other instance like (v12) it worked fine there to so what might be the problem for this ?