The standard for Pally is palletizing to two pallets.
But you can use the custom pallet feature to create a virtual pallet where you create your two pallets. This way you can palletize to 4 pallets in total.
Just remember to create space between the two pallets equal to the space you would need to place the two pallets on the factory floor.
By default the robot will palletize the complete first layer on both pallets before moving to layer 2, but you can use zones to completely palletize one pallet before moving to the next.
Read more about zones in this article: Pally knowledge base - Zones
Remember to start with the pallet farthers away from the pick up position. And when the pallet closest to pick up is complete, remember to move it beforte starting with the first pallet again. This will help you to easily avoid colliding with existing palletized boxes.
We also highly recommend simulating the setup to ensure you have enough reach etc.
By combining this with the dual product mode you can palletixe two product to 2 pallets. 1 product to the pallets on the left side and the other product to the pallets on the right side.
Read more about dual product mode in this article: Pally knowledge base - Dual product mode