How to troubleshoot a non-functional air conditioning in an Audi A1?

I recently bought an Audi A1 and the air conditioning doesn't seem to be working. Whenever I turn it on, it just blows warm air. What could be causing this issue and how can I fix it?

First, check if the air conditioning compressor is running. If it's not, it could be a problem with the electrical system. In this case, it's best to take your car to a qualified mechanic for further diagnosis.

If the compressor is running, then the issue might be a leak in the refrigerant. You can try adding some refrigerant yourself, but it's recommended to have a professional handle this as it can be dangerous.