Those who want to remap the Bixby button of their Galaxy Note 9 can do it thanks to the latest update received by the bxActions - Bix Button Remapper app for Android, which now sports full support for Samsung's latest high-end phablet. Thanks to this app, the Bixby button can be used to perform over 30 actions.
https://www.notebookcheck.net/Bixby-button-remapping-now-works-on-the-Galaxy-Note-9.325622.0.html