MySQL Where Clause By Last String

Question

i have a some data code like this :

1. PR 00001J
2. PR 00001B
3. PR 00002B
4. PR 00002J
5. PR 00003J

how i can get data only J with where clause ? is it need something like regex ?

i've been try with this query but the output was NULL

SELECT MAX(request_code) as max_request_code FROM `request` WHERE RIGHT('request_code',1) = 'J'

anyone can help me out ?

Thank you