How to view the native Roman and Arabic pages

I’m trying the free version of pdftron but I wanted to know how to view the native Roman and Arabic pages of the pdf, I followed the documentation PDFTron Systems Inc. | Documentation or https://www .pdftron.com/documentation/samples/node/js/PageLabelsTest or PDFTron WebViewer Class: PageLabel but nothing. Dove am I wrong? Can you give me a hand?
Thanks Giuseppe

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Hi @pesce88, this forum is for PDF.js Express and not WebViewer. For WebViewer support please get in touch with us here.

Thanks!
Logan