How do I get a key for the Office 365 API?

Question

Microsoft

At work, there was a task to connect using JavaScript and PHP mail for Office 365 users, looking for information, I came across that it is possible using the Office 365 REST API, but I still didn’t understand where to get the key for use ( https://msdn.microsoft. com/en-us/office/office365/... ), I understood only one thing - you need to buy a subscription, there are a lot of different subscriptions and which one I need to buy so as not to make a mistake and God forbid I buy some other Microsoft product ..
Maybe someone has come across this and knows where to get the Office 365 API key ?

Answer 1

What a pity that squeamish specialists don't even know how to google normally, but run to the toaster to express their disdain for the "crafts" of the Evil Company.
blogs.msdn.com/b/exchangedev/archive/2014/09/24/10...
The link tells how to register your application, get a token and make requests to the O365 REST API and through it to Exchange. Do not disdain English, I hope?

Answer 2

I read this article, did as it says, except for the broken link in the first stage, now I get this nice error:
AADSTS70001: Application with identifier ******************* ******* was not found in the directory
************************** , I find out that the causes and solutions of this error are different for everyone, which means that this error is also given by the "Evil Company" servers for any problem, thanks for that, I'll go google further