How to Call URL in API Nested Array

I'm new to REST API and am having some trouble. I'm trying to call data from an array that's nested within a dictionary. While I've been able to pull data from other variables fine, this is giving me some problems. For reference, the URL I need is labeled "front default," inside the "sprites" array. Furthermore, the URL is that of an image, and I am using Alamofire Image to display images. I will include the code I've used thus far to call other variables, along with a link to the API.

https://pokeapi.co/api/v2/pokemon/pikachu/

import Foundation
import Alamofire
import AlamofireImage
import SwiftyJSON
import Siesta
class PokeInfo {
    var name: String
    var id: Int
    var abilities: [String]
    var types: [String]
  
   
    /
    init?(jsonDictionary: [String: Any]) {
        /
        guard let name = jsonDictionary["name"] as? String,
            let id = jsonDictionary["id"] as? Int,
            /
            let abilities = jsonDictionary["abilities"] as? [[String: Any]],
        let types = jsonDictionary["types"] as? [[String: Any]]
        else {
                return nil
        };
       

        var abilityNames: [String] = []
         var typeNames: [String] = []
       
        /
        for abilityDictionary in abilities {
           
            guard let ability = abilityDictionary["ability"] as? [String: Any], let name = ability["name"] as? String else { break }
           
            abilityNames.append(name)
        };
        for typeDictionary in types {
           
            guard let type = typeDictionary["type"] as? [String: Any], let name = type["name"] as? String else { break }
           
            typeNames.append(name)
        }
       
        self.name = name
        self.id = id
        self.abilities = abilityNames
        self.types = typeNames
    }
}