Quiero reproducir audio en la carga de la página usando este código

 <audio id="player"> <source src='{{url}}'/> </audio> <progress min="0" max="100" value="0"></progress> <div class="hp_slide"> <div class="hp_range" id="rangeslider"></div> </div> <button id="playbtn" (click)="start_audio()">Play</button> start_audio() { var button = <HTMLVideoElement> document.getElementById("playbtn"); var audio = <HTMLVideoElement> document.getElementById("player"); button.addEventListener("click", function(){ if(audio.paused){ audio.play(); button.innerHTML = "Pause"; } else { audio.pause(); button.innerHTML = "Play"; } }); var element:HTMLElement= document.getElementById('playbtn') as HTMLElement element.click(); audio.addEventListener("timeupdate", (e)=>{ var ct = audio.currentTime; var duration = audio.duration; var slider =document.getElementById('rangeslider'); slider.stop(true,true).animate({'width':(ct +.25)/duration*100+'%'},250,'linear'); });

conseguir que esta propiedad de error se detenga no existe en HTMLELEMENT.