Order entry for spreads

Hello. I have recently just put out a system here at C2, and after watching the order entry tutorial video and fiddling with the New Signal entry screen, I was unable to figure out how to enter an options spread order. If anyone is aware of how to do this, I’d be much obliged. Additionally, does C2 fill limit orders entered at the mid, or must one buy at the bid and ask of options to be filled? Thanks.