use the qrcode package from An­ders O. F. Hen­drick­son to generate the QR codes directly in LaTeX

[Magger]

It might be a good idea to use the qrcode package from An­ders O. F. Hen­drick­son to generate the QR codes directly in LaTeX instead of generating them externally in a website.

See: https://ctan.org/pkg/qrcode?lang=de

Therefore, the existing qrcode command in the poster template must be renamed e.g. to 'qrcodeposter' using:

\let\qrcodeposter\qrcode

before loading the qrcode package.