How about a reliable, working v-training site that doesn't spit out the following error at least 85% of the time?

Welcome to nginx!

If you see this page, the nginx web server is successfully installed and working. Further configuration is required.

For online documentation and support please refer to nginx.org.
Commercial support is available at nginx.com.

Thank you for using nginx.

Trying to go to https://v-training.m5stack.com/ results in a "Welcome to nginx!" message.
Trying to go to https://docs.m5stack.com/en/quick_start/unitv2/v_training results in a "Server error An error occurred in the application and your page could not be served. If you are the application owner, check your logs for details." error

Any ideas?