How do we modify the chat prompts?

[Routhinator]

Hi there, I was working with qwen3-code:4b-instruct as a test to see how it does over the qwen2.5-coder:7b-instruct and after crafting a detailed prompt for it, it got turned around as I requested that it write code and not explain itself but the default prompt was telling it the opposite.

I've seen where I can modify the templates for right click actions, but not how to edit the chat prompts. Also curious if we can add custom right click actions with completely custom templates while we're on the topic of prompt customization.