When you insert a storage card that has not been used on
HTC U12+ before, the card will be mounted as removable storage by default. If the storage card is new or doesn't have content you want to keep, you can format it as internal storage for
Home screen, swipe up and then tap
Portable storage, tap
next to the storage card name.
Follow the onscreen instructions to move your installed apps and their data from the built-in storage to the storage card.