How do you use replacingOccurences(of:)? I continue to get an error -> Value of type 'String' has no member 'replacingOccurences'

I am having trouble with using replacingOccurences(of:) to replace text in my string. I've tried to import Foundation but I still get an error -> Value of type 'String' has no member 'replacingOccurences' This is my code:

let randomDog = dogNames.randomElement()!                                                             
var replaced = randomDog.lowercased().replacingOccurences(of: " ", with: "_") //PROBLEM
replaced.append(".jpeg") //fixing file name                                                                            
let image = UIImage(named: replaced)//display image

I have Xcode version 13.4.1.