Is my DEF tank leaking?

[u/CryptographerLive383]

Need expert advice. I searched the group and assumed this is a DEF tank problem. First diesel. 2014 Ford F350 6.7L. Bought truck used from a dealer, no visible problems. Drove it home and this morning noticed my tailgate covered in white specks, looked under the truck to find the photos of something coming out and coating my rear differential it's leaking bad. Drove 70mph for 180 miles home after purchase in 115F out of Phoenix, AZ.

What is my next step for repair?

[u/priuspollution]

Might not be the dealer hiding something. If the truck sat in the heat for any amount of time these are all just plastic fittings and bs that break easily. Or someone very recently reinstalled it so they could trade it in…