I just putted this at the final where const lineLengthExtension = 2.2, lineLengthReduction = 2.2;.

pointsToConnect.forEach(({ angle }, pointIndex) => {
        const innerPoint = polarToCartesian(innerOuterRadius - lineLengthReduction, angle);
        const inclinedOuterAngle = angle + (pointIndex === 0 ? inclinationAngle : -inclinationAngle);
        const extendedOuterPoint = polarToCartesian(outerInnerRadius + lineLengthExtension, inclinedOuterAngle);

        svg.append("line")
            .attr("x1", innerPoint.x)
            .attr("y1", innerPoint.y)
            .attr("x2", extendedOuterPoint.x)
            .attr("y2", extendedOuterPoint.y)
            .attr("stroke", lineColor)
            .attr("stroke-width", 3);
    });