1991 Toyota Celica airbag light

Yes, I had someone put in a new clutch and I dont know what he did but my airbag light stays on is there a plug for the airbag under the car I dont know because I cant find it maybe you can be kind and tell me where the plug is for the airbag hook up under my car please or do I need to reset the computer and how do I do that but im pretty sure its a plug somewhere by the transmishion under the car or some where under the car please help me out I am broke and I cant aford to have a shop or dealer ship do it. Thank you