I installed Google Keyboard (Gboard) to replace the keyboard on my Samsung phone and the first thing I needed to make sure I had was the number row. It required me to enable it for it to be shown. Here's how to enable the number row on Gboard.

1. Tap in a text area of an app to activate the Google Keyboard (Gboard)

Open up a web browser or any app that has a text area and tap in a text area to open up the Google Keybaord.

2. Tap on the Gear icon at the top of Google Keyboard to open Settings

3. Tap "Preferences"

4. Toggle the switch to enable the "Number row"

The Number Row should now be enabled

Now you'll be able to click the back button until you are back to your app where you enabled the Google Keyboard and you should see the number row on top.