When closed the strut has to be mounted the length of the strut from the back wall(with a strut with a mount at the top, otherwise that is where the top of the strut should land and your mount is down in the keezer...). When closed that puts the top right at the collar top for the bracket for the lid... When extended open the lid and move the lid mount to where the strut is fully extended and look at the angle, you want about 45 degrees or so. If it is less move the bottom mount out towards the back of the collar, If it is more then move it in towards the front of the collar... One of those play with it until it looks good things... long as you get full extension it will work. Picture the angle between the collar and the strut fully extended, that should be about 45 degrees give or take to make it function the best. more is better than less than 45 because you lose lifting capacity...
Hard to explain without pics lol but I have built several mounts to move antennas, car doors and trunks etc with electric actuators and you learn quick what works.