How to get contacts with outlook365?

Question

Outlook

Faced such a problem, it is necessary to get contacts from a specific outlook email address, previously used imap . Now the client does not want the password to be stored in this program.
First of all, the thought came to look at api . All the examples that I have seen on the Internet require manual user authorization. That is, a link is generated, the client follows it, then redirects back to his project with an authorization code (which comes in get).
This option does not suit me, since contacts are downloaded according to a schedule daily in automatic mode.
I would like to see an example of obtaining an authorization code without user action (click on a link), for example, through curl . Is it possible? Or did I miss it somewhere and didn't see it? Has anyone faced a similar issue?
I do not need any authorization, there is one specific email address and I need to regularly download contacts from it. (app on apps.dev.microsoft.com created key and app code available)