I really like Q-Bell style (sometimes called clamp) bicycle bells. I wear it like a ring around my index finger, then use my thumb to sound the bell. There are a number of brands if you search for them, but this is the one I use now:

https://www.amazon.com/Bicycle-Suitable-Handlebars-Bicycles-Mountain/dp/B08HWNBTCB

They generally come in two sizes with the smaller able to fit around my index finger without gloves (I have one and almost never use it) and the larger able to fit around gloves (which I use all the time). I usually do some slight modification to make it more comfortable on my finger. Here is a picture:

https://img.glaciated.org/q-bell.jpg

They are designed to fit different handlebar sizes, so I adjust to fit my finger the same way, but super glue the spacer on which, on handlebars, would normally be kept in place by pressure.