[QUESTION] how to use {{TEMPLATE:}} syntax

[GamerGirlandCo]

sorry if this is a stupid question... it says here that {{TEMPLATE:<TEMPLATEPATH>}} allows you to include a template in your format.

i created a template to be used by a capture choice, that looks something like this:

---
title: {{VALUE:Title}}
type: {{VALUE:outline,story,ideas,tasklist}}
somevar: {{TEMPLATE:z/templater/testplate}}
---

however, {{TEMPLATE:z/templater/testplate}} doesn't change to the template contents. am i doing something wrong? should i not be using a capture? apologies once again, i'm really new to this plugin 😅