Hello @HyoJun Park ,
Welcome to Q&A Forum!
According to my research, there is currently no way to check the failed files and reupload these to SharePoint Online via SPTM.
You can refer to the below workaround:
1.Naviagtion to the following path: ** C:\Users\<account>\AppData\Roaming\Microsoft\MigrationTool\domain.onmicrosoft.com\<TaskID>\Report\ **

2.Open the FailureSummaryReport.csv
3.You can see the details of these failed files when the migration process

4.You need to manually upload these failed files to SharePoint Online


For more information, please see "Monitoring and reporting status of migration tasks" article.
Thanks,
Echo Du
=====================================
If the answer is helpful, 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.