This hard drive from Western Digital has room for 2 TB of data. This model has a 2.5" form factor.
From Amazon
WD_BLACK P10 Game Drive for Xbox 2TB, portable external HDD, On-The-Go Access To Your Xbox Game library, Includes a 1-month membership of Xbox Game Pass Ultimate, transfer speeds up to 130MB/s
This product is also available at 5 unverified stores.