Add optional headers parameter for webhooks in notify API command

API.md

@@ -2459,6 +2459,7 @@ Required parameters:
     body (str):             The body of the message
 
 Optional parameters:
+    headers (str):          The JSON headers for webhook notifications
     script_args (str):      The arguments for script notifications
 
 Returns:

plexpy/api2.py

@@ -421,6 +421,7 @@ class API2:
                 body (str):             The body of the message
 
             Optional parameters:
+                headers (str):          The JSON headers for webhook notifications
                 script_args (str):      The arguments for script notifications
 
             Returns:

plexpy/helpers.py

@@ -1179,6 +1179,7 @@ def split_args(args=None):
                 for arg in shlex.split(args.encode(plexpy.SYS_ENCODING, 'ignore'))]
     return []
 
+
 def mask_config_passwords(config):
     if isinstance(config, list):
         for cfg in config:

plexpy/notifiers.py

@@ -3613,6 +3613,7 @@ class WEBHOOK(Notifier):
                        }
 
     def agent_notify(self, subject='', body='', action='', **kwargs):
+        subject = kwargs.get('headers', subject)
         if subject:
             try:
                 webhook_headers = json.loads(subject)
@@ -3631,7 +3632,7 @@ class WEBHOOK(Notifier):
         else:
             webhook_body = None
 
-        headers = {'Content-type': 'application/json'}
+        headers = {'Content-Type': 'application/json'}
         if webhook_headers:
             headers.update(webhook_headers)