video not playing - page load


I have a video that is playing if i click a button in my site but when page load (first page in my site) it is not playing!

urlpatterns = [
    path('', views.firstpage, name="first-page"),

def firstpage(request):
	return render(request,'firstpage.html',{})


   <video autoplay loop>
        <source src="{% static 'cart/slider/sale.mp4' %}" type="video/mp4">

when i go to the site the video is there but it is not playing. if you open the video in other tab or page it will play. Also i have a button in my page called “Announcements” if clicked it will go to the page “firstpage.html” and the video will autoplay!

take a look at my site:
My site

Looks like its chrome and other browsers settings. Sadly I dont think it possible to force that! I went to IE and it is ok but chrome I had to allow soiund in settings. If anyone knows any workaround it will be great.