Example of simple OAuth2 authentication using Alamofire 5 and RxSwift library

extension Api {
    
    enum OAuth2Service {
                
        static func getUserAccessToken(username: String, password: String) -> AuthorizedEndpoint
    {
            
   return 
   AuthorizedEndpoint(
                
   raw: 
   Endpoint(
                    
   authType: .
   basic,
                    
   method: .
   post,
                    
   path: 
   "oauth/token",
                    
   parameters: [
                        
   "username"
   : username,
                        
   "password"
   : password,
                        
   "grant_type"
   : GrantType.
   password
                    ]
                )
            )
        }
       
   ...
    }
}
  

 
 let client = AuthorizedClient<Scope.Guest>()
 
 client
    .request(Api.OAuth2Service.getUserAccessToken(username: username, password: password))
    .asObservable()
    .subscribe(
        onNext: { accessToken in
            DispatchQueue.main.async {
                // Store access token
            }
        },
        onError: { error in
            DispatchQueue.main.async {
                // Handle api error
                guard let errorResponse = error.asApiError?.response else {  
                    ...
                    return
                }
                ...
            }
        }
    )
    .disposed(by: disposeBag)