1. Betta's belong in 5 gallon heated and filtered TANKS not bowls. They're tropical and need heated water and clean water.
2. Sunlight on a bowl will overheat it (during the day) and freeze it (at night) creating a drastic change in temperature which your fish will neither appreciate nor survive for long.
3. The only way you'll keep a live plant alive for long is if you can an FLUORESCENT light. LED, incandescent (most aquarium lights) do not have the wave length live plants require. That plant will rot and foul up your "bowl".
4. Flaring is a sign of aggression as well as agitation. They do not light strong direct light.
Solutions:
1. Purchase a 5 gallon+ tank, instal a small gentle filter (red sea makes a good nano HOB filter) or sponge filter, a 25 watt heater set to 80
2. Get an fluorescent light or get a plant that does well without one (java fern, java moss, anubias, hornwort).
3. Get a light that is dimmer.
4. NEVER put your tank in direct sunlight. It causes unsightly algae, and dangerous temperature swings.