"Drying cannabis in a box before curing."

Since that's the only way you can do it, it's totally fine—the cardboard itself naturally absorbs moisture, so don't worry too much. Just poke a few small holes in the box to prevent excessive humidity from building up inside. Keep in mind that the paper you're using underneath looks like it has notebook ink on it. I'd avoid that at all costs if you want to preserve the aroma, as the ink can affect the terpenes and the paper will get soggy. Instead, use a fine mesh or just place them directly on the clean cardboard bottom. Avoid aluminum foil, as it traps moisture underneath the buds. Also, always keep the box closed so no light gets in, but leave those small openings to allow air to circulate. Lastly, make sure to spread them out and avoid stacking the buds on top of each other, as this can cause unnecessary mold growth.