Lawson Laslows latch
We installed https://www.homedepot.com/p/Everbilt-Satin-Nickel-Steel-Window-Sash-Lock-with-Tight-Seal-20306/301015629 window latch for our side windows.
Simply attached with 2 screws per window and it then easily latches, You can keep it latched and move the 2 windows together to get ventilation on one side.
Lawson Laslow