Playing the T-Rex game (or Chrome Dino game) in Google Chrome is quite simple.
Use the spacebar to make the dinosaur jump over obstacles (cacti) and the down arrow key to duck under obstacles (pterodactyls).
The game continues until you hit an obstacle. After that, you can start over by pressing the spacebar again.
If you want to access the game while still connected to the internet, you can do so by typing chrome-dino.com into your address bar and pressing Enter. The game will appear, and you can start playing by pressing the spacebar.