Step 1: cut paper
Take baking paper, cut it according to the tube's lenght and add 2-3cm from both sides.
Step 2: put paper inside
Roll paper and put it inside the tube by leaving 2-3cm from each side outside of the tube.
Step 3: cut ends vertically
Step 4: tape
Tape each slice/cut to the tube one by one.
Step 5: put LED strip inside
Put all leds inside except one. Bend it to the outer side of the tube. Close the cap.
Step 6: connect to controller
You can use any controller for leds, I decided to use the one from Magic Home, because it is compatible with smart home system that I'm using.
Connect another end of LEDs to controller and close the bottom part.