According to docs
Handle messages in a backgrounded app
When your app is in the background, Android directs notification messages to the system tray. A user tap on the notification opens the app launcher by default.
This includes messages that contain both notification and data payload. In these cases, the notification is delivered to the device's system tray, and the data payload is delivered in the extras of the intent of your launcher Activity.
If you want to open your app and perform a specific action, set click_action in the notification payload and map it to an intent filter in the Activity you want to launch. For example, set click_action to OPEN_ACTIVITY_1 to trigger an intent filter like the following:
<intent-filter> <action android:name="OPEN_ACTIVITY_1" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
Edit :
Based on this thread :
You can't set click_action payload using Firebase Console. You could try testing with a curl command or a custom http server
curl --header "Authorization: key=<YOUR_KEY_GOES_HERE>"
--header Content-Type:"application/json" https://fcm.googleapis.com/fcm/send
-d "{\"to\":\"/topics/news\",\"notification\":
{\"title\": \"Click Action Message\",\"text\": \"Sample message\",
\"click_action\":\"OPEN_ACTIVITY_1\"}}"