我明明有訂閱office 365 但 powerpoint 程式下載下來之後，總是說我:找不到授權

I've tried the way you told but it doesn't work.
I've removed the license and reinstalled the office 365 but It still show no license found.

Yes, thank you so much!! My Chinese is not the best. I can read Chinese, but writing is hard for me.

This is what you can try -

I do want to make sure you already tried logging out and logging back in. If that didn't work, use spotlight to open Keychain, type in Office and then delete the data license file.

Then use this instruction to remove the license file: https://support.microsoft.com/en-us/office/how-...

After that, I would like for you to sign back into Office app and see if it activates.

你可以用英文回覆給我，我看得懂，翻譯成中文後讓我有點困惑，謝謝