define entrypoint

pak/__init__.py

+from .hello import hello 
+
+def run():     
+    hello()
+

pyproject.toml

@@ -6,4 +6,7 @@ build-backend = "setuptools.build_meta"
 name = "pak"
 version = "0.1.0"
 description = "A simple Python package."
-authors = [{ name = "Your Name", email = "your.email@example.com" }]
+authors = [{ name = "Your Name", email = "your.email@example.com" }]
\ No newline at end of file
+
+[project.scripts]
+pak = "pak:run"