Send push notification from web api to user if date on data table == Xamarin.Android

I want to ask how to send push notification in Xamarin.Android. I making school project with and web.api for the database (sql server). I'm in trouble to send remote notification when the item data(date) in my table hit So every time the item in the table same as today date. the app send the notification even when the app not running. They said use firebase but how to get the date value?

Just asking for the procedure for that (not the code) cause i have no idea how to do it. I can send remote push notification but only when I trigger it (not because condition from table in my database).

Thanks in advance.