I can't get my game to run in the simulator in Xcode

I just finished a game and was ready to test in the iPhone simulator on Xcode. I saw that people had some problems with it online and that to have it run in the simulator, you needed to go to playerSettings > otherSettings > targetSDK > simulatorSDK, and then build and run. So, I did this and opened the project in Xcode, and the place where you can pick which device simulator you want to run (I've done it when messing around with app development) only has one option, and that is "My Mac." If I press play, it says "The run destination My Mac is not valid for Running the scheme 'Unity-iPhone'"

So, can anyone help me out? All the answers I've seen have been to make sure simulator SDK is checked, which it is, but I still can't get it to work.