How can I see past 48 hours location of my stolen I pad

Here is Apple’s advice for lost or stolen devices:

If your iPhone, iPad or iPod touch is lost or stolen – Apple Support

Use the Find My app to locate a lost or stolen device – Apple Support

If the Find My iPad feature was enabled prior to it being “misplaced”, then if active, you would stand a good chance of locating it. 

However, if the feature was not activated prior to being misplaced - or the iPad has been inactive for more than 24 hours, the last known location will not be available - and the opportunity to use technical means to recover the iPad have been lost. Location information is limited to the preceding 24 hours.

you can't get some route of locations

all you can get is what you see if you use a computer browser and login to www.icloud.com and use find my iphone from there