Hello community help marker and alert google maps

Hello kodular community, first I want to thank you for all your help and the magnificent answers you have given me, they are a great help with all my heart, thank you very much

secondly, could someone help me if there is any way to create a marker on a map and activate an alert on another device if that marker is near that device? Thank you very much for your answers I appreciate your time in answering us to all beginners