MMA/ LIFT TIG machine question

Hi guys, i was looking at the store at an inverter electrode machine who had a switch and you could with the proper torch do tig lift. I was intrigued since i wanted for so long a tig machine but i saw that the machine didn't had any hole or valve to plug in the gas tank. So my question is : How do you tig without gas? And another question is: If you can tig with this machine can you weld aluminum even if is only DC?