Switch to another subdomain in django on a click of a button

Question

I am actually having issues with template link of a button to point to my subdomain which actually if I enter it manually on a browser, it works just fine. I need something like this

{% load hosts %}
<a href="{% host_url 'homepage' host 'www' %}">Home</a>

But it doesn't work if i place the code above on a button. Am I missing anything?. Appreciate the help guys