Insert html in new line after pressing return/enter in QTextEdit -PySide6

[tIk90wT]

I'm trying to insert special characters at beginning of new lines in QTextEdit when I press enter/return, like how QTextList have decorations. But the following code inserts the html on the same line before moving to the next line.

class ed(QTextEdit):
    def __init__(self):
        super(ed, self).__init__()
        self.installEventFilter(self)

    def insertLine(self):
        cur = self.textCursor()
        cur.insertHtml("<span>&#10023;</span><span>&nbsp;</span>")
        self.setCursor(cur)

    def eventFilter(self, o, e):
        if e.type() == QEvent.KeyPress:
            if e.key() == Qt.Key_Return:
                self.insertLine()

I tried

KeyRelease

and it kind of works. But it starts inserting typed letters if i type fast while moving to next line.

I tried to make use of QTextListFormat but it doesn't support custom decorations.

Can I make use of QTextList to achieve what I'm trying to do?
How to insert the html after the cursor moves to next line, not before?