So that's about the maximum today. HP does not document changing the HDD or the HDD size. Try SPECCY https://www.google.com/#q=speccy if you can't find the HDD details. Then it's up to you to crack it open to clone and replace the HDD with a possible newer 2TB HDD of the right size.
Just bought HP Pavilion x2 Detachable 12-b020nr 12" Laptop. How to add more storage memory to it?