SFTP upload isn't enabled for your plan
Account SFTP panel shows account.sftp.tierBlocked (SFTP upload isn't enabled for your plan.). Closely related Help title: SFTP upload not enabled for your plan.
Why this happens
Users-limits / plan feature flag blocks SFTP for this tier. Distinct from site-wide disable or no eligible servers.
Diagnose and fix
1. Upgrade to a plan that includes SFTP, or ask admin to enable it for the tier.
2. See Buy Premium / Premium Pro if premium unlocks SFTP on this site.
3. See SFTP upload / Connect with SFTP.
4. If servers are the issue instead, see the no-upload-servers article.