Hey Markus
There are 2 possible options here. On the client’s site, they can purchase/use Event Aggregator to import events from any other site running The Events Calendar using the “Other URL” option.
Or…
Check out our latest event calendar tool that you can use on any content management system: Loxi.io. You can get started with a free trial today and see if it will meet your needs. If so, you are able to embed it on as many sites as you’d like.
Is there anything else I can help you with?
Thanks
Courtney 🙂