In theory, SSD storage can be connected to iPad and iPad Pro with caveats…
To be recognised by iPadOS, the attached USB storage device must be formatted to FAT, FAT32, exFAT, APFS or HFS+ with a single partition. Microsoft NTFS is not supported. Formatting and partitioning, if required, must be performed using a separate computer; iPad does not provide any facilities to format an external storage device.
As the iPad has limited power capabilities, dependent upon the Storage Device, an external power source is often required.
If you have one of the newest iPad Pro models, with a USB-C connector, you may need to utilise a powered USB hub (i.e., it has its own source of power) - connecting both the iPad Pro and the storage device to ports on the hub.
Some additional information can be found here:
Connect external devices or servers with Files on iPhone - Apple Support
https://www.imore.com/how-use-external-hard-drives-your-iphone-or-ipad
Be aware that your iTunes Music Library cannot be accessed by the iOS/iPadOS Music App. For your Music Library to be accessible by your iPad, the iPad must be synchronised with your Mac (using iTunes or Finder - as appropriate for the installed version of macOS) or a Windows PC (using iTunes for Windows). The sync’ process copies an authorised copy of the iTunes Music Library to the iPad - where it can be accessed using the Music App.