I have Microsoft 365 Personal, I'm office insider and I want to install TypeScript

Hello 2gg,

Are you trying to use it to write Office Scripts? If so, please check out this page: https://docs.microsoft.com/en-us/office/dev/scripts/overview/code-editor-environment#office-scripts-javascript-api 

If you're trying to do something else, please provide more information.

Thanks,

Evan