Recreational/hobby UAS pilot reported flying at night without an anti collision beacon.

Narrative

Night flight requires collision avoidance beacon. That was properly installed and operational; pre-flighted OK. Activation was via remote control panel. This was a new drone for me; so flight sequence was repeatedly: lift-off; try a feature set of the remote control; then land; shut down; look at the instructions; change settings (e.g. beginner mode; km/h or mph; etc) take off and try another feature set. Familiarization flights. The issue was when I was flying at about 243 ft. and a helicopter flew past ZZZ. We had safe separation (vertical and horizontal); but I decided to bring the bird down and noticed when it was landing that the anti-collision light was not turned on. This was my first day flying the aircraft and the feature familiarization affected situational awareness (SA); creating a violation.My guess is that I had changed batteries and forgotten to restart the light. Once airborne at about 30 ft.; the only indication to pilot (or crew; if we had one) of whether this light was working was an icon on the remote control. The bird was easy to follow visually from the standard lighting on its sides (especially at the small distance from me). From the ground it was not possible to see the flashing anti-collision light mounted atop the drone and I doubt the side lighting is visible at 3 SM.The system carries a camera that seems to operate continuously. If the software in this system could alert the operator to check for avoidance collision lighting when detected luminance falls below some threshold value (even if that were a selectable safety feature); that may reduce the likelihood of pilot error and improve flight safety.