SL buy order query

Why can’t “trigger price” and “price” be same while placing SL buy order?

Zerodha always forces to have “price” greater than “trigger price”. I have no issues doing that but 95% of the time Zerodha completes my buy order at “price” even though I could see many sell orders between “trigger price” and “price”.

I am asking about SL buy order.

Lets say the current price is 100. I want to buy only if it reaches 103. For that I will place SL buy order with “trigger price” at 103. But the problem is Zerodha ask to keep “price” greater than 103. Why can’t I have both as same value?

I used to do currency trading in different portal and there I could have both prices same.