A small addendum to better subscribe my problem:

odoo runs behind an apache reverse proxy -> https://odoo.mycompany,com works fine, also the Azure AD Single Sign On works fine.

My problem is accessing odoo via the standard odoo app for android. While connecting via app, i receive an 400-server-connection error (see log). So i have to
1.) disable csrf handling or
2.) remove the " unsafe HTTP method" in the build-in odoo webserver.

Adding the ssl_certificate(_key) options in the odoo.conf is a try for option 2.

Kind Regards
Steffen

########
WARNING odoo-enterprise odoo.http: No CSRF validation token provided for path '/'

Odoo URLs are CSRF-protected by default (when accessed with unsafe
HTTP methods). See
https://www.odoo.com/documentation/16.0/developer/reference/addons/http.html#csrf
for more details.

* if this endpoint is accessed through Odoo via py-QWeb form, embed a CSRF
token in the form, Tokens are available via `request.csrf_token()`
can be provided through a hidden input and must be POST-ed named
`csrf_token` e.g. in your form add:
<input type="hidden" name="csrf_token" t-att-value="request.csrf_token()"/>

* if the form is generated or posted in javascript, the token value is
available as `csrf_token` on `web.core` and as the `csrf_token`
value in the default js-qweb execution context

* if the form is accessed by an external third party (e.g. REST API
endpoint, payment gateway callback) you will need to disable CSRF
protection (and implement your own protection if necessary) by
passing the `csrf=False` parameter to the `route` decorator.

addendum 2

my "problem" is solved ... and the solution is so cheap :-).
There is no trouble with the webserver / reverse-proxy configuration ...

In the odoo servername field in the app we have not to put in the servername
i.e. odoo.company.org

in the servername field we have to put the URL
i.e. https://odoo.company.org).

Thats all

Thanks for your input. Addendum2 is clear and is what is told by odoo unfortunately not working form me, do not know why. I tried with both: https://mydomain.fr and https://www.mydomain.fr but still not ok.