I need another way to say "as is". I've tried to look up in every dictionary and thesaurus
Assuming you mean as-is in the sense of selling something as-is:
Informal expression that conveys that the thing in question may or may not be in perfect condition or work perfectly, and that it's up to the other party to determine that for themselves.
Literally buyer beware, this phrase means that the other party in the transaction agrees to assume any risk of a defective product.
This is a little bit more legal sounding, so I linked an article explaining more. Basically, there are expressed guarantees ("The car I'm selling runs great!") and implied guarantees ("I'm selling a car, not a picture of a car"). This phrase is an attempt to claim you're providing neither.