companion for betta

hi

i have a fish bowl for the past 1 month. it is fairly large, can fill
approx 3.5 gallons. i have a single male betta fish in the bowl, we
have a heater for the temperature. Me and my family are quite
frustrated with the absolute inactivity of this betta fish, it mostly
comes up near the top and hangs around the air bubbles (there is a
water plant). is it possible to say add maybe 2 guppy fish in this fish
bowl. we are not interested in a fish tank and would like to keep the
bowl only.

would like to know from you people if it will be possible to add 2
guppies (of the same sex) to our current setup without any undesirable
results. or if the guppies are not a good idea then any other fish
which could help us out of our predicament.

all your feedback will be appreciated, thanks.

Ash.