How to add Warlock Pact Weapon in Character Sheet

Hi, How do I add a conjured pact weapon into my character sheet? Is it as simple as finding the weapon and dragging into equipment then setting the weight to 0? Or is there a specific way that considers the item as magical?

You can just use a normal weapon and rename it. There is no real marker in the game to say if it is magical or not, so you just have to remember it and the DM most likely know. However. I don't know where you got the idea that the Pact Weapon doesn't have any weight. Nowhere in the Pact of the Blades does it say it is weightless. You just get to summon a magical weapon, which include its weight as long as you are holding it.