Why does the T99 only come with one car key?

Two keys.

Ask the 4S store. A key costs 600 yuan.

It seems like there might be some context missing or a typo in your message. Could you please provide more information or clarify what you need help with?

I do have some skills.

That's how the manufacturer designed it. 😁

I also have one, and a digital car key on my phone. 🔑