You can’t make them do it
I hear this quite a lot from parents, it’s not that you want to make them go to class its more about advising them and encouraging them as to why they should go.
If you just accept that they are telling you they don’t want to go then you’re not finding out the reasons and therefore are not finding a solution to the problem.
In stead of just accepting it sit down with them and ask them to explain why they don’t want to go.
Sometimes it might be they are tired, sometimes it’s because their friends are doing something else (or just nothing). They will find excuses and your job is to be prepared with a solution. A push in the right direction is not a bad thing. Over the years I have taught and coached juniors and seniors to a high level, British, European and World Titles. They had their excuses and reasons not to come training but their parents saw the bigger picture and got behind them and pushed them on. Without their support the students would not have made it!
It’s easy to just say “oh well they don’t want to do it anymore” etc, etc. People who get somewhere are the ones who did not quit, they pushed forwards even when they didn’t feel like it. They had their parents, relatives, fellow students, coaches right there with them.
Instil a belief in them. If you doubt them then they will doubt themselves. Be positive and encourage them to reach further. Tell them about people who didn’t give up, who went through hard times, self-doubt and negativity.
You don’t want your child or yourself to give up every time there is a hurdle, a problem. Solve it and move forwards.
Champions are made from within, dig deep and persevere.