You've got two options here.

The first option is to default the PDF format within the report definition itself. You can do this in Report Designer by going to the report properties, going to the Behavior -> Common Settings section, and setting ViewPdf to True.

https://i.imgur.com/8yx0Vpv.png

This will cause anyone running the report to see the PDF version first, although they can still switch back to HTML if they'd like.

The second option is something that a user could do on their own by going to the Print and Email Settings tab when they run the report and checking the Print in PDF format checkbox in the screenshot below.

If they want that checkbox to be checked by default when they run the report, then all they have to do is click the SAVE TEMPLATE button and save it as their default template. See screenshot below.

https://i.imgur.com/HdBLGIL.png

I've noticed that a report designed with Acumatica Report Designer can be displayed in two formats: HTML or PDF.

But it seems like HTML is the default format.

Is there a way to default the display of a particular report to PDF?