Hello everyone!
I can’t upload archive through FileZilla. I’ve already checked “FTP uploading guide”:
I’ve created API token, used case-sensitive Login, updated FTP client, but there’s NO result. I’m receiving 503 error anyway. Please, help me! 
P.S. I also tryied a few other FTP clients and still no result.
Hi
An error like: ‘530 Login authentication failed’ indicates that your token is invalid. You will need to create a new token. You need to create a Personal Token (Use the token as your FTP password) here: https://build.envato.com/create-token/
It is a good idea to create a token specifically for FTP access.
Please take care the following:
Encryption: Use explicit FTP over TLS if available
Logon Type: Ask for password
Username: [your Envato Market username] (this is case-sensitive)
Password: [your Envato Market API key]
Thanks
When you create your token, also make sure it has the “View your account username” permission. This is required, otherwise you will get 503’d.
Thanks a lot!
This was the actual problem.