I used 5x1mm magnets but you can use magnetic tape and cut to size, links below:

https://amzn.to/3LSPHvq https://amzn.to/3ZSo37r

Pay attention to the candle. Only LED candles, with batteries, NEVER PUT CANDLES ON FIRE!!!!!

You can and should put padding between the walls but it is also possible to print without it, but the final result may not be as good.

3D printing settings To print I used Cura and temperatures at 210º and 60º for the PLA bed