This demand partner does not support multi-size Placement ID (PIDs) where a single Placement ID (PID ) can get a bid request for multiple size creatives.
Step 1: Reach out to your demand representative and check if they support multi-sized requests with a single Placement ID (PID).
Step 2: If not, request the ad representative to provide you with a separate Placement ID (PID) per ad unit, per size.
Step 3: Deploy properly in the configuration.