You should. The voice recognition works FROM the keyboard, so depending on which one you use, you should see the microphone somewhere to start dictating. BUT this will only show if the keyboard is active (so tap on a text field first).
Now, since you own a Samsung phone, you have a couple more options for voice to text:
1) If you use the stock Samsung keyboard and you have the Bixby key enabled, you can tap on a text field and pressing/holding the Bixby key will automatically start voice recognition to type.
2) If you use GBoard as your keyboard, you can select Google Voice Recognition as the default keyboard (so that every time you tap on a text field that's the default mode it'll start with, skipping the keyboard altogether).