This question from seven years ago asks about turn signal lights for bicycles, but the consensus seemed to be that it's better to just use arm signals. What if it's not possible to safely do this? My kickscooter is way too twitchy to steer with one hand, but I would like to be able to signal properly.
Electronic turn signals seem to be commercially available, I found some listed by searching for "bicycle turn signal light". Still, I think folks are rarely going to regard an electronic signal since it's not common enough for them to be in the habit of looking, bright sunlight would probably reduce its effectiveness, etc. I suggest not to rely on signaling being observed or understood to keep out of danger; it's nice to have, but more fundamental traffic participation behavior should be used to establish safety boundaries depending on the rider's comfort level, risk/danger evaluation of a given physical environment and dynamic traffic situation, etc.
The only alternative I see are turn signals, but it doesn't look like there are 'established' products. A search in a online shop would give you plenty of references, (online) bike shops seem to ignore them though.
Some are small lights that you can install on your seat tube, helmet or bag pack, some are integrated to jackets and display big arrows on the jacket or lights that you install on end of the handle bar. All feature a remote that you install on the handle bar.
The only ones that stand out for me are the ones showing arrows in the jackets ...if they can be visible in day light (I'm not posting link as I don't have any personal reference, and it seems that most are same products sold from unknown/ephemeral brands). The rest is too small to be able to clearly show a direction and/or may not clearly distinguished from other lights that can exist in an urban environment. As a driver, I would not think to look at biker's helmets to see if there are turn indicators, so I'd rule out also the ones on helmets.