So, you got fired and now you're "on the market". You're worried that you won't find a job. Someone probably told you that you will "never work again". That is simply untrue. Being fired isn't the kiss of death. You can work again.
I have hired fired people. My sample size is small, but nearly all of those have turned out to be great hires!
So, how do you pull it off?
First, you need to admit it. The most important thing is to not lie. When I ask you, "Tell me why you are no longer with Acme Company" don't hide the fact you were fired. Be honest. Plus, hiring managers and recruiters can usually tell if you're lying. And starting off an employment relationship with a lie is not very smart. If you were fired because you did not perform well, say so. Perhaps you were in the wrong role and now you're looking for a job more in line with your skills.
Secondly, you need to know how your previous employer will handle a reference check . Call and ask for a reference, or verify prior employment. It's entirely possible that you won't like the answer, but at least you'll know.
Having been fired is a red flag, but not as big of a red flag as letting the interviewer wonder if you're being honest with her.