I have seen a ton of posts about schools putting together curriculum videos and online classes for their students should they need to stay home during the pandemic.
I would do something different.
You want people to be excited to come back to train when this is all over. Whether you have to close or some people just choose to pause classes for now, there should be motivation for them to want to return. Online courses and videos could potentially have some people thinking they can just do this at home, so why go back?
Here is my idea - everyday post up a fitness or martial arts challenge that your students can do at home. Have them take a video of them doing the challenge and then post it up and tag you. Your job would be to keep track of the challenges and who completes them. Reward those students who complete them with something when they return - a special stripe on their belt, a certificate, a tshirt, etc.
This would keep them active and training, connected with your school, and give them motivation to get right back into their normal routine of coming to class when things calm down.