[Solved] Cannot create accelerator with '>' character

I am trying to create an action with the keyboard shortcut Ctrl + S in a GTK4 Python application. I am using the boilerplate code given by GNOME Builder:

def create_action(self, name, callback, shortcuts=None):
        """Add an application action.

            name: the name of the action
            callback: the function to be called when the action is
            shortcuts: an optional list of accelerators
        action = Gio.SimpleAction.new(name, None)
        action.connect("activate", callback)
        if shortcuts:
            self.set_accels_for_action(f"app.{name}", shortcuts)

to create an action inside a window like this:

self.get_application().create_action("stop", lambda *_: print('stop'), "<primary>s")

When I launch the application, I get this in the terminal:

Gtk-CRITICAL **: 20:24:56.305: Unable to parse accelerator '>': ignored request to install accelerators

How should I create an accelerator with that shortcut?

I am no expert and could be very wrong here, but have you tried <Primary>s (with uppercase P)?

set_accels_for_action() takes an array of strings, not a single string.