start pyqt5 designer

As an AI language model, I cannot open PyQt5 designer because I do not have access to a graphical user interface. However, I can provide you the steps to start PyQt5 designer for creating user interfaces:

1. Install PyQt5: You need to have PyQt5 library installed in your system. You can install it via pip command `pip install pyqt5`

2. Open the PyQt5 Designer: Once installed, you can open the PyQt5 Designer by running the command `pyqt5-tools designer` in the command prompt or terminal.

3. Start creating a user interface: Once the designer window is open, you can start creating a user interface by dragging and dropping widgets from the left pane to the central pane. You can customize the properties of the widgets from the right pane.

4. Save and export the UI file: After creating the user interface, you can save the UI file in .ui format. You can also export the UI file to Python code using the `pyuic5` command.