How to use sub agents?

I'm sort of new to all this and got the DeepSeek API set up with Codewhale currently. I've heard great things about sub-agents and from what I understand, it lets better models (V4 Pro) automatically give away tasks to cheaper models (V4 Flash). Now the question is how do I actually use them? Or is that not supported in Codewhale? I actually asked the Ai for this but it just said that it’s basically already baked in but I gave it simple tasks throughout the day and my usage is like 98% V4 Pro which seems li