Board Game Arena

I must be missing something but I am stuck.

I am in my first game, we have 2 fleets in the same hex and the message "You may choose a retreat location".
I do NOT want to retreat and cannot find a way to stay in the same hex and alow combat to continue.

How do you stay and continue the combat ?

There is should be a "No Retreat" button at the top of the window.
If not, then it is a bug and should be reported.