Для этого вы можете использовать URLComponents, URLComponents определяется в Foundation.
var components = URLComponents()
components.scheme = "http"
components.host = "ctesterst.net"
components.path = "/api/Customers/homeData"
let queryItemLat = URLQueryItem(name: "lat", value: "12.456")
let queryItemLong = URLQueryItem(name: "lng", value: "76.786")
let queryItemAppVersion = URLQueryItem(name: "current_app_version", value: "123")
let queryItemDevice = URLQueryItem(name: "current_device", value: "something")
let queryItemToken = URLQueryItem(name: "access_token", value: "Km3R2AbU0yzAcVkp9BCxmCmaoC5k20fBiQxfLhIBIAolwJGgYw5w5E8X0NZzlDh8")
components.queryItems = [queryItemLat, queryItemLong,queryItemAppVersion,queryItemDevice,queryItemToken]
print(components.url)