Multi-Robot Frontier Exploration

I am trying to have multiple robots do frontier exploration (like tutorial_8). Basically, multiple robots would explore an unknown area. They would share the map with each other so that no robot will go into an area has already been mapped. They would continue to do this until everything has been completely mapped. I wanted to ask how I could do this? I’d appreciate any help.

Example video: multi robot autonomous map exploration - success in "Cave" map - YouTube

We do not have tutorial for multi-robot exploration.
There are some works which may help:

You will have to build your own solution based on above examples.