要将ARKit的ARCoachingOverlayView本地化为西班牙语，您可以按照以下步骤进行操作：

1. 在项目中创建一个名为Localizable.strings的新文件。确保将文件添加到项目的目标(即在“File Inspector”中选择正确的目标)中。

2. 在Localizable.strings文件中添加以下键值对，将其值设置为西班牙语翻译：

"ARCoachingOverlayView.Goal.Fit" = "Ajustar";
"ARCoachingOverlayView.Goal.HorizontalPlane" = "Plano horizontal";
"ARCoachingOverlayView.Goal.VerticalPlane" = "Plano vertical";
"ARCoachingOverlayView.Goal.AnyPlane" = "Cualquier plano";
"ARCoachingOverlayView.Goal.PlaneDetection" = "Detección de planos";
"ARCoachingOverlayView.Action.FindPlane" = "Buscar plano";
"ARCoachingOverlayView.Action.Reset" = "Restablecer";
"ARCoachingOverlayView.Action.Cancel" = "Cancelar";

3. 在您的代码中，使用NSLocalizedString函数来本地化ARCoachingOverlayView的相关字符串。例如：

let coachingOverlayView = ARCoachingOverlayView()

coachingOverlayView.goal = .verticalPlane
coachingOverlayView.goalInstruction = NSLocalizedString("ARCoachingOverlayView.Goal.VerticalPlane", comment: "")
coachingOverlayView.setActive(true, animated: true)

这样，当您的应用程序在西班牙语环境中运行时，ARCoachingOverlayView将自动显示西班牙语本地化的字符串。