Not able to exclude a wallet from rewards

We created a token using Dxmint (from the dxsale site) and I'm not seeing a "excludefromrewards" function under the write contract area in bscscan. I need for the reflections to our main supply wallet to be turned off. I can turn off fees which only prevents from fees being charged but no option to exclude from reflections rewards. Is there another way I can call that function? I'm new so please help me understand.