How to name a mission and avoid the name of the island

[Joe98 92]

I could do this easily in Arma 2

I could do this easily in Arma 3

Then there was a major update to the editor so I don't know how to do it any more

I named a file   Red Widget One 

And it came out as:  Red%20Widget%20One.Altis

Using underscores I changed it to:  Red_Widget_One.Altis

Now, how do I get rid of the name of the island?

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