Zero doesn't exist

Can you tell me a number that doesn't require the concept of zero to exist?

roman numerals had no need for 0

They still needed the concept of zero. Numbers cannot exist without it.

If I had one apple, and I sold it to your mom, how many apples do I have left?

It's a place holder for nothing.

why

Zero is the opposite to numbers, i.e. it is the lack of a number.

1 is 1.
1 is also the lack of any other number other than 1. That requires the concept of zero.

Something and nothing has to exist for the something to have a concrete boundary

All you need to count is 1 and 2

I'm not following?

You don't need 0 to count. You need 1, and you need the next number to establish a reference point. That's 2. Once you have 1 and 2, you have all the other numbers too since you now know the distance between 1 and 2.