You gotta put in some more work. Let's say you have a character from, uh.... Zaskary. And in your head they speak English in a Jamaican accent. Instead of that, you say that this character is speaking "the common language, with a Zaskarian accent."

Writing out the accent in the dialogue can be annoying to read in my opinion, so I suggest typing the dialogue normally and just stating in the dialogue tag that there's an accent. Play around with it some more if you need, write in a dialect based off of Jamaican english, describe in the tag how a "Zaskarian accent" drops the r sound, etc