can I use those refrigerant in a can as a seal for my air condition which has s

Hello, No, never use those. Really. The "sealant" in those cans will damage professional a/c evacuation and recovery equipment, and if it is noticed under the cap on the service ports, you will likely be refused service. How air could be caused by a bad blend door actuator, bad fuse, or an issue with the refrigerant system, so it may not need a major service. First, check to see if the compressor turn on when you turn on the A/C. If not, check your A/C fuses, and the relay for the compressor (if it is not integrated into an A/C control module). Then, turn off the engine, turn on the A/C to the lowest setting, and see if you hear the actuators under the dash when you adjust from full hot to full cold. If you hear them turn, you have eliminated that from the suspected failures as well. If none of these pan out, I recommend seeking professional diagnosis.