How to use "-beta" & "-betapassword"?

[bilibili-fire]

I want download a old beta version from a game, I know the beta branch and the password, but I can not get the beta.

PS G:\Downloads\depotdownloader-2.4.7> .\DepotDownloader.exe -app 1017410 -depot 1017411 -beta developalpha -betapassword TetraProjectDevelopAlpha -manifest 4788471046129651827 -username XXXXXX -password XXXXXX
Connecting to Steam3...Connection to Steam failed. Trying again
Done!
Logging 'qjchs' into Steam3...Disconnected from Steam
This account is protected by Steam Guard.
Please enter your 2 factor auth code from your authenticator app: XXXXX
Retrying Steam3 connection...Connection to Steam failed. Trying again
Connection to Steam failed. Trying again
Done!
Logging 'qjchs' into Steam3... Done!
Using Steam3 suggested CellID: 199
Got 76 licenses for account!
Got session token!
Accepted new login key for account qjchs
Got AppInfo for 1017410
Using app branch: 'developalpha'.
Got depot key for 1017411 result: OK
Processing depot 1017411 - Tetra Project Content
Downloading depot manifest...Got manifest request code for 1017411 4788471046129651827 result: 4293858687864145265
Done!
Manifest 4788471046129651827 (2020/1/10 7:57:16)
Downloading depot 1017411 - Tetra Project Content
Pre-allocating depots\1017411\5885267\MonoBleedingEdge\EmbedRuntime\MonoPosixHelper.dll
Pre-allocating depots\1017411\5885267\MonoBleedingEdge\etc\mono\2.0\Browsers\Compat.browser
......

Everything is preety good, but when it's done, I still don't get the beta game.

Did the beta game have another manifest? If it's ture, i think it will be over......
Thanks for your reading anyway.