..a small self-contained physical button that can be pressed with a an LED that can signal a notification.
Not talking about the likes of the amazon thing, just want something that can connect via bluetooth to a phone.
Something that could be stuck on a bike.

I’ve looked on google and turned up nowt, possible that my searching powers are poor today.

Cheers.

“Theoretically” you can program any bluetooth device to perform an operation of your choice.
Try searching for something along those lines.

this looks worth investigating…

amazing what slightly different searches reveal.

https://www.alibaba.com/product-detail/Mini-beacon-with-button-and-LED_60435553971.html

Yep what your looking for could be something like this, all depends on what use case/s your looking to achieve

I’ve written an app for a delivery company. The cyclist receives notifications on their phone about new orders. Problem is, with traffic noise they are missing the notifications. I wouldn’t feel comfortable asking them to wear headphones so they hear the notifications. I’ve suggested giving them all a mount for their phone on their bike so they can see it coming in., but this has potential problems too. So, I was thinking of a button on the bar that will flash when they receive an order and they can press the button to confirm they’ll do it.

Bargin…

But does what you want. Even different colour less.

https://www.lupine-shop.com/en/accessoires-and-parts/remote-control/1323/bluetooth-remote

My Garmin vivoactive watch vibrates when i get certain types of messages – far more noticeable than the phone in traffic.

Maybe a connect IQ app for a garmin. My garmin watch will receive
Notifications from my phone. My 520 did too.

Could you not just use an RFID or NFC tag?

User waves it over the RFID/NFC sticker on the bike, etc?

if they have internet connection then something based on Internet of Things?