The command is unknown, but swapping one confusable character (0/O, 1/I, 5/S, 2/Z, 8/B) gives exactly one real command. The suggestion is only made when the candidate is unique.
^XA^FO50,50^A0N,40^FDHELLO^FS^FO50,120^G8300,60,3^FS^XZFinding: ZPL1003 · line 1:39 — Unknown command: ^G8 — did you mean ^GB?
Open the broken label in the editor →
Accept the suggested command; the quick-fix replaces it in place. Then check the parameters still fit the intended command.
^XA^FO50,50^A0N,40^FDHELLO^FS^FO50,120^GB300,60,3^FS^XZOpen the corrected label in the editor
ZPL1001 Unknown command · ZPL1002 Command not supported by the renderer
npx labelixa validate "labels/**/*.zpl" lints your files and prints this page's address next to each finding. /docs/cli