How to impelement "or" contains search

hey guys

I wanna realize “or” contains search like this in SQL

select *
from XX
where XX.A like ‘a%’ or XX.A like ‘b%’.

I read some FAQ and understand there is no way to implement “contains search”
and ,instead of it, I need to use search keyword.
I think i will work in my case.
but I don’t know how to write query to implement “or search keyword”.

if you have knowledge, please let me know.
my language is kotlin