Every institution using Canvas has a URL for their Canvas environment that is in the format xxx.instructure.com where xxx is the name of the institution. The URL you've quoted there https://canvas.education.lu.se is what's sometimes called a "vanity" URL - an alternative version of your Canvas URL that's been created to be easier for your users to remember. To get to your beta environment you need to know your main Canvas URL (rather than the vanity URL) and add the word "beta" to it.
It looks like you're at Lunds University so I would guess that your institution's Canvas URL is lu.instructure.com and if that's correct then your beta environment would be lu.beta.instructure.com
If that doesn't work, log a call with Instructure support through the help menu in Canvas and they will be able to tell you the correct URL