For assembly, you also need
1x LED 5mm of any color
1x switch (12*8MM DC 30V 1A On Off Mini Push Button Switch for Electric Torch 1208YD Self Locking)
1x lithium battery charging module (Battery Quick Fast Charging Board IP2312 CC/CV Mode 5V To 4.2V)
1x battery (3.7 V 301230 031230P 110mAh polymer lithium battery)
and second glue