A big part of your job as a coach is to encourage and support your client towards their goal(s). If a client is falling behind, do not be afraid to call this out.
Tracking milestones attached to specific dates is a great way to keep your clients accountable for their progress. Set milestones with your client upfront (e.g., We will do 2 mock interviews before August 31st) and if they don’t meet these milestones, make sure to send them a message.
Of course, you cannot force a client to do anything, but rather, as a coach you can nudge, encourage, and cheer them along.
And lastly, when you help your client reach their goal, ask for a review!