I can't log into institutional email using outlook ("Need admin approval")

I followed this guide, but I always encounter the same problem (How do I add an Office365 account?). It’s my university email. I don’t have the same problem with Thunderbird on Windows. Can someone help me? Thanks in advance.

I can’t upload more than one image, so I’ll put the others here: Imgur: The magic of the Internet.

It’s exactly as the errors indicate: You need an admin from your Alma mater to approve K-9 to access your account.

All MUAs come with a unique application ID that needs to be granted access. Whatever is not on the whitelist gets blocked.

Get used to it… Many corporate policies that do not include BYOD or are very strict about security will present you with the same issue. You need to convince the admin that your MUA is safe and adheres to corporate policies; they might then add your MUA to the whitelist.

So Thunderbird is approved but K-9 Mail isn’t? What can I do? I just wait K-9 Mail to get approved by who, Microsoft or my University?

As I wrote: your Alma mater.

Thank you very much!