(ArcGIS API for JavaScript) Sample of how to add an arrow to the end of a line in the Legend using js

Sample.js

//Make sure the layer is loaded, the query all path elements and add the attribute to the specific path you want
fl.on("update-end", (e) => {
        document.querySelectorAll("* path").forEach((e,i) => {
            if(i === 3){
                e.setAttribute("marker-start", "url(#marker_map_0_0_0_start)");
                e.setAttribute("marker-end", "url(#marker_map_0_0_0_end)");
            }
            console.log(e);
        }); 
    });