anchor.diff:                  id = <<"s3_timeout">>,
                   style = <<"width: 30em; display: block">>,
                   placeholder = <<"Timeout [ms] (optional)">>
  +            },
  +            #flatui_checkbox{
  +                label_id = <<"s3_sig_v2_checkbox">>,
  +                label_style = <<"width: 20px;">>,
  +                label_class = <<"checkbox">>,
  +                delegate = ?MODULE,
  +                postback = sig_v2_toggled,
  +                body = <<"Signature version 2">>
               },
               #flatui_checkbox{
                   label_id = <<"s3_readonly_checkbox">>,
  
positive.code:                 State;
  
              {s3_submit, StorageName, AccessKey, SecretKey, Hostname, BucketName, BlockSize, Timeout} ->
                  OptArgs = prepare_opt_args([{timeout, Timeout}, {blockSize, BlockSize}], []),
                  Insecure = maps:get(insecure, State, false),
                  Readonly = maps:get(readonly, State, false),
                  case onepanel_gui_logic:add_storage([{StorageName, [{type, <<"s3">>},
  
negative.code:                 Readonly = maps:get(readonly, State, false),
                  maps:put(readonly, not Readonly, State);
  
              sig_v2_toggled ->
                  SigV2 = maps:get(sig_v2, State, false),
                  maps:put(sig_v2, not SigV2, State);
  
              {ceph_submit, <<>>, _, _, _, _, _, _} ->
                  onepanel_gui_utils:message(error, <<"Please provide admin username.">>),
                  State;
  