Anki addon development: Error creating an editor button

I'm trying to add a button in Anki toolbar.

It worked!

But, when I click the button, it show me an error message, it seems an event listener.

What I need to do?
I tried to implement onBridgeCmd, but it doesn't work (I don't know how to implement).

def blur_text(editor):
    showdialogtitle(editor.currentField, 'anki')

def addBlurButton(buttons,editor):
    editor._links['blur_text'] = blur_text    
    buttons += [editor._addButton(ICON_PATH, "blur","Blur Text")]
    return buttons 

addHook("setupEditorButtons",addBlurButton)

Error:

Debug info: Anki 2.1.35 (4e12c7ef) Python 3.8.5 Qt 5.12.2 PyQt 5.12.1 Platform: Linux Flags: frz=False ao=True sv=2 Add-ons, last update check: 2021-01-21 14:27:50 Add-ons possibly involved: ⁨Anki IPA, blur_text, search_in_dictionaries⁩

Caught exception: Traceback (most recent call last): File "/snap/anki-woodrow/27/lib/python3.8/site-packages/aqt/webview.py", line 37, in cmd return json.dumps(self.onCmd(str)) File "/snap/anki-woodrow/27/lib/python3.8/site-packages/aqt/webview.py", line 123, in _onCmd return self._onBridgeCmd(str) File "/snap/anki-woodrow/27/lib/python3.8/site-packages/aqt/webview.py", line 547, in _onBridgeCmd return self.onBridgeCmd(cmd) File "", line 2, in onBridgeCmd File "/snap/anki-woodrow/27/lib/python3.8/site-packages/anki/hooks.py", line 638, in decorator_wrapper return repl(*args, **kwargs) File "/snap/anki-woodrow/27/lib/python3.8/site-packages/anki/hooks.py", line 635, in repl return new(_old=old, *args, **kwargs) File "/home/element/snap/anki-woodrow/27/.local/share/Anki2/addons21/search_in_dictionaries/init.py", line 230, in on_bridge_cmd _old(editor, command) File "", line 2, in onBridgeCmd File "/snap/anki-woodrow/27/lib/python3.8/site-packages/anki/hooks.py", line 638, in decorator_wrapper return repl(*args, **kwargs) File "/snap/anki-woodrow/27/lib/python3.8/site-packages/anki/hooks.py", line 635, in repl return new(_old=old, *args, **kwargs) File "/home/element/snap/anki-woodrow/27/.local/share/Anki2/addons21/blur_text/init.py", line 59, in on_bridge_cmd _old(editor, command) File "", line 2, in onBridgeCmd File "/snap/anki-woodrow/27/lib/python3.8/site-packages/anki/hooks.py", line 638, in decorator_wrapper return repl(*args, **kwargs) File "/snap/anki-woodrow/27/lib/python3.8/site-packages/anki/hooks.py", line 635, in repl return new(_old=old, *args, **kwargs) File "/home/element/snap/anki-woodrow/27/.local/share/Anki2/addons21/799647424/main.py", line 183, in on_bridge_cmd _old(editor, command) File "/snap/anki-woodrow/27/lib/python3.8/site-packages/aqt/editor.py", line 385, in onBridgeCmd (type, ord, nid, txt) = cmd.split(":", 3) ValueError: not enough values to unpack (expected 4, got 1)

The problem was the button's event name, I needed to change it, for some reason, "blur_text", is used in the Anki system.

def contrast_text(editor: Editor) -> None:
    ...

def add_contrast_button(buttons: List[str], editor: Editor) -> List[str]:
    button = editor.addButton(ICON_PATH, "contrast", contrast_text)
    buttons.append(button)
    return buttons

addHook("setupEditorButtons", add_contrast_button)