You can watch the British Open on Sky Sports if you are subscribed, or you can watch it live from your sportsbook account. For instance, William Hill has one of the best streaming services around. To make use of it, all you have to do is:
Sign in: log in to your William Hill account.
Head to Golf: go to the Golf Betting page and find The Open.
Start streaming: click on The Open and start watching The Open live.