Smooth Svg Path

Need to achieve smoothness in svg path element.

This is an example path out of my projcet:

    let svg = document.querySelector("#mouse-trail");
    let lastMousePoints = [];
    let maxVertices = 20;
    let buffer = [];
    let bufferSize = 20;

    svg.addEventListener("mousemove", function(e) {
        addPoint(e);
    });

    function addPoint(e) {
        let pt = {
            x: (e.clientX),
            y: (e.clientY)
        };
        buffer.push(pt);

        if (buffer.length > bufferSize) {
            pt = getAveragePoint(buffer, bufferSize);
            lastMousePoints.push(pt);
            buffer.shift();
        }

        if (lastMousePoints.length > maxVertices) {
            lastMousePoints.shift();
        }

        let pointsString = "M ";
        for (let i = 0; i < lastMousePoints.length; i++) {
            pointsString += lastMousePoints[i].x + " " + lastMousePoints[i].y + " ";
        }
        if(lastMousePoints.length>0){
            circle.setAttribute("cx",lastMousePoints[lastMousePoints.length-1].x);
            circle.setAttribute("cy",lastMousePoints[lastMousePoints.length-1].y);
        }
    
        path.setAttribute("d", pointsString.trim());
    }

    
    function getAveragePoint(buffer, bufferSize) {
        let len = buffer.length;
        let totalX = 0, totalY = 0;
        for (let i = 0; i < len; i++) {
            totalX += buffer[i].x;
            totalY += buffer[i].y;
        }
        return { x: totalX / len, y: totalY / len };
    }


        setInterval(function(){
        lastMousePoints.shift();
        let pointsString = "M ";
        for (let i = 0; i < lastMousePoints.length; i++) {
            pointsString += lastMousePoints[i].x + " " + lastMousePoints[i].y + " ";
        }
        if(pointsString != "M "){
            path.setAttribute("d", pointsString.trim());
        }
    },15)

I tried this but in fast movements I still see sharp cuts. I don’t knwo what I’, missing.

reference https://jsfiddle.net/Gowtham0415/L510mqwp/4/

Much thanks in advance, G