Problem with Collabora Online Server

I want to install Collabora Office on ownCloud. Still, I found error message as follows.

Collabora Online unknown error: Client error response [url] https://x.x.x.x/hosting/discovery [status code] 404 [reason phrase] Not Found

Do I have to create a collabora online server? How do I do so?

You need to set up a collabora server first, see CODE-Install and Test - Collabora Office and Collabora Online.