How to get your API key
An API Key can be "connected" to one specific event (can only access data of that event) or to a user account (can access all events of that user).
But the easiest ways to get your API key is by creating one in the frontend of your user account after logging in to your account on www.xing-events.com.
When creating an API key you can select what type of API key it should be and with that define to which calls the API key has permissions for. If you create an API key for yourself, just create an "administrator" key to get access to all calls, but if you want to forward the key e.g. to a partner, think about restricting the key so your partner has only the access he needs to fulfil his task. In the documentation of each call, you can find the respective role needed to access it.
Create an API key with access for one event
Go to https://www.xing-events.com/mycenter/events.html, select the event you would like to have access to and create a new API key at the menu item "Edit Event -> Permissions".
Create an API key with access to all events of your account
Log in to the account you want to grant permission to, go to https://www.xing-events.com/mycenter/settings/apiKey.html,
or click on My Account.
Create a new API key with user permission in the API key tab.