Airbag light stays on all the time?

That's not much detail to go on. Without knowing the history that led up to this, or what you've done or checked so far, the place to start is by having the diagnostic fault codes read and recorded. Those will tell us where to start the diagnosis. If you don't have a scanner, you'll need to visit a mechanic to have the code read. Here's a link to an article that shows how this is done:

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

Once you know the exact code numbers, post them in your reply, then I'll look up the definitions for you and the typical troubleshooting steps.