In your dashboard, you can see all the roles that are available to you.

You can click 'View details' and you can see more about the role. If you'd like to be considered for this position, then click 'I am interested in this role'.

Back in the dashboard, all the roles that you're interested in and have been extended formal offers will look like this:
​

By clicking 'View details', you'll go through to this page:
​

Click 'I accept the formal offer' if you'd like to take the role. You must do this within 90 seconds or it'll time out.

Once you've accepted the offer, you're contractually bound to the position specified. You'll receive an email  and text to confirm, and the page will look like this: