Let's see how good you are at this.
Define objective morality.
Give some examples of objective morality.
That you can do this: not influenced by personal feelings or opinions.
Another way is to find a way to ground it in objective evidence.
Do you want actual examples?
Okay, that good and bad and right and wrong are out there in other humans, their behaviors and/or beliefs.
In general any objective morality centers it being independent of the person doing it.
Another variant is utilitarian and if you like better for the group.
Sam Harris used an indirect approach: Define harm in way we can all agree on and then let science do the rest.
Classical modern examples are the assumption of universal human rights. To some humans they are as natural as nature itself and thus objective. Property rights in modern western culture are to some objective.
Another variant is with reason and logic. Find something which follows from reason and logic.