._.

Desktop/main.py

@@ -1,3 +1,11 @@
+import sys
 
+from PyQt6.QtWidgets import QApplication
 
+from main_window import MainWindow
 
+if __name__ == '__main__':
+    app = QApplication(sys.argv)
+    window = MainWindow()
+    window.show()
+    sys.exit(app.exec())

Desktop/main_window.py

@@ -0,0 +1,9 @@
+from PyQt6 import uic
+from PyQt6.QtWidgets import QMainWindow
+
+
+class MainWindow(QMainWindow):
+    def __init__(self):
+        super().__init__()
+
+        uic.loadUi('ui/main.ui', self)