Here you have a blank white board holder.  I ordered these from Amazon:

[https://www.amazon.ca/dp/B09Z7SDS2X?ref=ppx_pop_mob_ap_share](https://www.amazon.ca/dp/B09Z7SDS2X?ref=ppx_pop_mob_ap_share)

They fit in perfectly, but I would suggest a dab of glue to hold them in place.  There are 4 holes in the back to add 8 x 2 magnets, if you wish.  They will also require a dab of glue

If you would like to add writing, open in Bambu Studio, click on the model. Click on the “T” on the top right menu bar, right beside the paint tool. Choose your font, choose your text. On the left, choose object, then choose text, then choose colour. Place your text where you like it, resize using the text menu. I would recommend choosing 2mm as your thickness for the text. Print face up, choose colours by object for text, or paint using the paint tool. No AMS Required, just add a pause to switch filaments if you add text.  I suggest clicking detect thin walls, or using arachne wall generator if you add text.  Also, use a nice thick font for best results.

Have Fun!!