I have designed a box for the Alex wardrobe from Ikea that works in conjunction with the Celta organizer. The dimensions are identical. The top and bottom parts are held together by magnets that need to be inserted during printing. Simply pause the print just before the magnet pocket is closed and insert a magnet. Then resume the print. Done!
Magnets i used: https://www.amazon.de/dp/B01LX5H8O6?ref=ppx_yo2ov_dt_b_product_details&th=1
The author remixed this model.