Hi I am using the message module https://www.drupal.org/project/message with drupal 8 to log information. I was able to get the date and time in the messages produced by adding a token of the date and time , but I want to add a customized message that is different each time. How can I do this? this is the code I am using:

 $message = Message::create(['template' => 'sfbu_progress']);  
 $message->save();

How can I add a customized message to each message created? Thank you.