When you insert a new SD card, Android asks how to use it. The choice decides what you can move to it.

	Portable storage	Internal storage (adopted)
For	Photos, music, videos and files	Apps and app data, as part of the phone storage
Use in other devices	Yes	No, it is encrypted for this phone
Move files to it separately	Yes	No
Remove the card	Safe after ejecting	Apps and data on it stop working

What APPtoSD shows

"Android on this phone moves apps to this card: App info → Storage → Change." Your card works as it is.
"No Change button in App info?" Some phones move apps only to an SD card formatted as internal storage. Your card is set up as portable storage.
"This card is formatted as internal storage": Android moves apps to it from App info → Storage → Change; files can’t be moved to it separately.

Change the format

Formatting deletes everything on the card. Copy your files first, then follow How to Format an SD Card as Internal Storage.

Use a fast, genuine card for internal storage. Check it with the Full capacity check first: a slow or fake card makes apps slow and can lose data.