LanguageTool browser extension with Office 365 online

I’m using LanguageTool in my browsers.
Our company started using Office 365 (online - in the browser), but I noticed that LanguageTool doesn’t work there.
Am I missing something? AFAIK it should work in (almost all) text fields.
Any idea?

Word isn’t supported by our browser add-on, but you could try using our older MS Word add-on. It doesn’t underline the errors directly in the text, though.

Thank you for your reply.
Do you know if Word (online version) will be supported in near feature?

I don’t think support is planned for the add-on in the near future.

Is it a technical problem? Maybe Microsoft use too complex editor?

Yes, it’s not just a text field or a standard editor like 99.9% of all other websites out there.