Pdf.js: How can i open links to new tab / window

Since there's no information provided about how you're using PDF.js, e.g. just the API or the entire default viewer, the general approach for specifying the target attribute is to place e.g.

PDFJS.externalLinkTarget = PDFJS.LinkTarget.BLANK;

somewhere before the PDFJS.getDocument(...) call in your code.
Please refer to global.js for a list of the possible values that PDFJS.externalLinkTarget accepts.

Closing as answered.

I don't know if this helps anybody, but in a few examples in this repository PDFJSLIB.PDFLinkService is used to render links. Setting PDFJS.externalLinkTarget = PDFJS.LinkTarget.BLANK; did not work with this implementation but the below code did.

    pdfLinkService = new PDFJSLIB.PDFLinkService({
      externalLinkTarget: 2
    });

@Snuffleupagus I tried

PDFJS.externalLinkTarget = PDFJS.LinkTarget.BLANK;

instead of:

PDFJS.openExternalLinksInNewWindow = ( PDFJS.openExternalLinksInNewWindow === undefined ? false : PDFJS.openExternalLinksInNewWindow);

but unfortunately to no effect :( What else can I do to check or try?

Running Opigno LMS = Drupal 7 which uses /sites/all/libraries/pdf.js/build/pdf.js

UPDATE:
After I upgraded from pdf 7.x-1.9 to the current 7.x-1.x-dev version with drush and cleared the cache it is working now :)

Actually having removed it again it's still working, perhaps it's integrated in the new dev version of the drupal module.

app.js：
let pdfLinkService = new PDFLinkService({ eventBus, externalLinkTarget: 2, externalLinkRel: AppOptions.get('externalLinkRel'), });