Fix a flat is okay for tires if you need to do a quick repair and don't have a spare tire to replace the leaking tire with or you just have a slow leak.
But be aware that Fix A Flat can damage TPMS Sensors and will need to be cleaned off of Rims and tires when you have the tire properly repaired.
It's best to have the tire repaired properly with a patch which will be much better and not damage your rims or TPMS sensors.
If you do put the Fix A Flat in your tires let the tire repair shop know because it can be dangerous to them.