Momentary click-button switch

Does anyone know of a place to get a lightweight, small momentary pushbutton LoRa switch?
The Use Case is for my employees to carry a small device that can either be worn, put in pocket, or attached to a keychain that my remote employees on the campus can either click the input device once or twice to transmit the clicks to another LoRa device with a receiver. It needs to be small and not too expensive, like a remote garage door opener using 433MHz. I looked everywhere and cannot find. It can’t be too hard to make …. single LoRa transmitter, button and watch battery, right? Many thanks!!