i cannot download an update software

What happens when you try? How are you trying to update your iPad? Wirelessly or using a computer?

Should be the former, have you followed all the steps provided in this support guide?:--> Get help with over-the-air iOS updates – Apple Support

Regards

GIulio

What software update - an App, or iPadOS? What are you attempting to acheive?

Do you see any error messages - and if so, what are they - and when do you see them?

What is your current version of iPadOS?

With the benefit of more information, perhaps we can provide some appropriate assistance.

My router/modem/DSL work fine for everything except that trying to download the most recent updates for iPhone, iPad, and Mac crashes my internet service. It’s like it forces the modem/router to reboot itself.

I’m working with my internet service provider but they haven’t been much help yet.

What version of iPadOS 13 is your iPad Pro currently running?

The current officially released version is 13.4.1.