onclick function called without clicking the button

I have the content script of a chrome extension containing a function which is supposed to fire only when a particular button is clicked. But I notice that the function is fired once when the button is clicked and it keeps on calling itself multiple times( not infinite)

 button.addEventListener("click", handleButtonClick);

 function handleButtonClick() {
        extractedData = function3();
        // Your custom logic for button click
        setTimeout(() => {
            fillContentEditableWithDummyText('Loading...')
         
            fetch('a valid end point',{
                method: "POST",
                body: JSON.stringify({
                    email: user.email,
                    extractedData: extractedData
                })
            }).then(res => res.json()).then(data => fillContentEditableWithDummyText(data.message))
        },300);
        //fillContentEditableWithDummyText();
    }

When I tried to debug, noticed that once function3() is returned, the handleButtonClick() function is called again