Hi Jin,
My apologies, For MAC OS try this steps for quick repair:
Quit all Office applications and make sure all Microsoft 365 apps is closed.
Uninstall Microsoft 365 for MAC
Open Finder then open Applications. Press Command The Command button + click to select all of the Microsoft 365 for Mac applications. Then press Ctrl + click the application you selected and click Move
to Trash then restart your MAC.
For more information you can check this article from Microsoft: Uninstall Office for Mac
https://support.microsoft.com/en-us/office/uninstall-office-for-mac-eefa1199-5b58-43af-8a3d-b73dc1a8cae3
Install Microsoft 365 for MAC
If you don't have Microsoft Office 365 installer you need to sign in and download it. If already had a Microsoft Office 365 installer proceed with steps.
Go to m365.cloud.microsoft/apps and if you're not already signed in, select Sign in.
Sign in with the account you associated with this version of Microsoft 365 or Office. This account can be a Microsoft account, or work or school account.
After signing in, follow the steps that match the type of account you signed in with.
double-click Microsoft Office installer.pkg file (the name might vary slightly).
On the first installation screen, select Continue to begin the installation process.
Review the software license agreement, and then click Continue.
Select Agree to agree to the terms of the software license agreement.
Choose how you want to install Microsoft 365 and click Continue.
Review the disk space requirements or change your install location, and then click Install.
Enter your Mac login password, if prompted, and then click Install Software. (This is the password that you use to log in to your Mac.)
The software begins to install. Click Close when the installation is finished.
For more information you can check this article from Microsoft: Download, install, or reinstall Microsoft 365 or Office 2024 on a PC or Mac
https://support.microsoft.com/en-us/office/download-install-or-reinstall-microsoft-365-or-office-2024-on-a-pc-or-mac-4414eaaf-0478-48be-9c42-23adc4716658#installsteps=install_on_a_mac
Let me know how this goes. If you need more help please feel free to message me.
Best regards,
Jansher