In case something bad happens to 88.io, you can use the 88-io.com domain.
88-io.com is currently operating in backup mode, designed to be used when 88.io has problems.
It will be upgraded to mirror mode sometime in year 2024, so it can be used concurrently with 88.io. That is, either 88.io or 88-io.com can be used at anytime for any operation.