Low vent air flow

I would like to change out the cabin air filter in this vehicle for better air flow whether using the heat or A/C. However, this model is not equipped with one. I assume that there has to be a permanent, built-in cabin air filter so my question is where is it located so that I can try to clean it off? Over time, just like cabin air filters that need to be replaced. I am pretty sure the ones built in vehicles has to be cleaned for quality.

I have searched that there is not one, but it only seems right that there is something there to keep fresh air flow. The issue is restricted air flow no matter what the setting. I feel the presence of cold air, but it does not blow out strong. With it on high, it feels as if it is barely at 1. Evap and heater core's are new as well as blend doors and actuators.