in excel-addin/src/commands/commands.js [10:23]
function action(event) {
const message = {
type: Office.MailboxEnums.ItemNotificationMessageType.InformationalMessage,
message: "Performed action.",
icon: "Icon.80x80",
persistent: true
};
// Show a notification message
Office.context.mailbox.item.notificationMessages.replaceAsync("action", message);
// Be sure to indicate when the add-in command function is complete
event.completed();
}