Chances are that some connection in the airbag wires has come slightly adrift. There are yellow wires around the car that control the airbag sensors.
You'll find many threads on this.
Basically, if you have access to this, read the faults and try to identify which airbag/wire it is which is throwing the fault. Clear the fault and see whether it (and the light) comes back. If it comes back, some work is involved.
Disconnect the battery and let the car sit for an hour or two to make sure the airbag circuit is de-energized.
Now disconnect the connector or connectors in the airbag system which are throwing the error and clean them and tightly refit them or replace them with better connectors or solder them together properly.
Then reconnect the battery. If the airbag light is off, you have fixed the problem. If it is still on, hook up the car to the diagnostics again and clear the fault. If it comes back, you have still not fixed the problem. If it stays off, you have fixed the problem.
If it is still on then, a few possibilities remain:
1. You have not properly fixed the problem with the wire(s) you worked on.
2. The problem is actually somewhere else in the circuit, possibly including in the airbag controller or in the airbags themselves, or simply on another connector on another wire.
3. (Very unlikely) the light itself is faulty but the system is fine.