Why won’t my iPad charge? Port cleaned.

Does the cable insert fully? Sometimes debris gets in the port and is so thoroughly squished in the bottom of the port that it looks like nothing is in there, kind of like a false bottom.

Assuming the port is indeed clean and you have tried Apple original cables as well, the only other option is to have the charging port replaced. Unfortunately, on the iPad Air that requires some soldering so unless you have those skills, you will need to find a shop that does micro-soldering repairs.