sign AppAPI requests with update method to support httpx.Headers

Signed-off-by: Alexander Piskun <bigcat88@icloud.com>

Author: bigcat88

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 All notable changes to this project will be documented in this file.
 
+## [0.5.1 - 2023-11-xx]
+
+### Fixed
+
+- `headers` can now be `httpx.Headers` and not only `dict`. #158
+
 ## [0.5.0 - 2023-10-23]
 
 ### Added

nc_py_api/_session.py

@@ -424,7 +424,7 @@ def _create_adapter(self) -> Client:
         return adapter
 
     def sign_request(self, headers: dict) -> None:
-        headers["AUTHORIZATION-APP-API"] = b64encode(f"{self._user}:{self.cfg.app_secret}".encode("UTF=8"))
+        headers.update({"AUTHORIZATION-APP-API": b64encode(f"{self._user}:{self.cfg.app_secret}".encode("UTF=8"))})
 
     def sign_check(self, request: Request) -> None:
         headers = {