Now, I have a new error (nginx-error):
FastCGI sent in stderr: "PHP message: PHP Fatal error: _PhpScoper99e9e79e8301\TheNetworg\OAuth2\Client\Provider\Azure::request(): The script tried to execute a method or access a property of an incomplete object. Please ensure that the class definition "TheNetworg\OAuth2\Client\Token\AccessToken" of the object you are trying to operate on was loaded _before_ unserialize() gets called or provide an autoloader to load the class definition in /var/www/vhosts/domainname.com/httpdocs/wp-content/plugins/mail-integration-365/libs/vendor/thenetworg/oauth2-azure/src/Provider/Azure.php on line 164" while reading response header from upstream
