You usually need to buy a single "credit" (around $20–$35) from vendors like Canada Unlocking or Martview.

Sony’s "TA" partition logs unlock events. Even if QUnlockTool hides the flag from Android, Sony service centers have deeper diagnostic tools. If you ever send your phone for repair, they will deny coverage. qunlocktool sony

You would buy a one-time login from a reseller. You usually need to buy a single "credit"

If you are researching qunlocktool sony , you need to understand the workflow. Do not attempt this unless you are prepared for data loss. qunlocktool sony