Hi @Taehwan Kim ,
Welcome to Microsoft Q&A!
The app registered in the Microsoft Store can't be deleted , it is recommended to hide the app through Discoverability.
Thank you.
If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".
Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.