Basic UTF-8 setup
Use ^CI28 before fields that contain Unicode text. If characters still print as boxes, check font support on the target printer.
^XA
^CI28
^PW812
^LL406
^FO50,80^A0N,36,36^FDOlá, München, 東京^FS
^XZReproduce a missing glyph
Compare an ASCII field with café at the same position. ^CI28 selects UTF-8 interpretation; it does not install a font. If only the non-ASCII field fails, inspect font coverage, downloaded font configuration and printer firmware. If both fields clip, inspect positions and dimensions first. Labelary font support may differ from your physical printer; these examples do not imply a hardware test.
^XA
^CI28
^FO20,20^A0N,30,30^FDcafé^FS
^XZ