As I understand it, from a Qlik perspective, your users are just clicking on a link. Whatever that link directs to (in this case, a PDF) is external to your Qlik solution. How would you expect multiple PDFs to be downloaded without the appropriate links being clicked? This depends on the target of the link - if it can take multiple documents as a parameter, you can create a link with multiple documents in it and have the users click that.
the "target" can take only 1 parameter per time. The software we were using before Qlik was allowing to download for example 100 pdf files with one click, the user who use the dashboard by selecting for example "last month" had a certain number of invoices and by clicking select all he had the possibility than to download all of them in one time...they would like to have it here as well...
Invoices was loaded in that software with the same api.domain.com/directory etc...
I don't think there's any obvious way for Qlik Sense to open a bunch of links in a single action. Perhaps through Automation if you're in Qlik Cloud?
You could also set up some sort of redirect where the original link has all of the required IDs and then that gets broken down into individual links on the redirect page and sent to the target domain.
