Swift iOS15 async/await + basic authentication + http request slow(er) - ios

Question

I am using the below code for basic http authentication. It is noticeably slower than when I wasn't using authentication (the below is called around 30 times)
Are there any speed optimization changes that could be made to the code ?
Thanks
struct PrixJSONService {
let passwordString = "user:password"
let configuration = URLSessionConfiguration.default
enum PrixJSONServiceError: Error {
case failed
case failedToDecode
case invalidStatusCode
}
func fetchPrix(for stationId:String) async throws -> [Prix] {
let passwordData = passwordString.data(using:String.Encoding.utf8)!
let base64EncodedCredential = passwordData.base64EncodedString()
let authString = "Basic \(base64EncodedCredential)"
let session = URLSession(configuration: configuration)
configuration.httpAdditionalHeaders = ["Authorization" : authString]
let dataUrl = "https://xxxx.xx/~xx/xxxxxxxx/prix/\(stationId)/price.json"
let url = URL(string: dataUrl)!
var urlRequest = URLRequest(url: url)
urlRequest.setValue("Basic \(base64EncodedCredential)", forHTTPHeaderField: "Authorization")
urlRequest.httpMethod = "GET"
let (data, response) = try await session.data(for: urlRequest)
guard let response = response as? HTTPURLResponse,
response.statusCode == 200 else {
throw PrixJSONServiceError.invalidStatusCode
}
let decodedData = try JSONDecoder().decode([Price].self, from: data)
return decodedData
}
}