Board Game Arena

How do you choose the number of armies to attack with? It's my turn and I'm trying to attack a neutral province and when I click on the province, it says I'm attacking with 0 armies

I've had the exact same issue and I wonder if this is a fault. Can anyone confirm. To be clear, I was Mr jack and were not visible at the end of the last turn and then attempted to move out of an exit. The exit (the space beyond the board) was 3 spots away the footsteps only went to the edge of the ...