dataLayer setup for goolge tag manage

Hi all,

I want to pass some dataLayer values when a form submit using ajax. So I have pushed into dataLayer when got response from ajax. But the GTM code is in the layout page. So when I submit a form only current part of ajax is reloaded as per ajax nature. So the data which I have pushed into dataLayer is not passed with GTM code as full page is not reloaded (Layout will update only if full page refreshed.)

Help me out to set dataLayer runtime.