Change credentials for Data Source

I am following the tutorials for reporting services on the microsoft website and currently on: this tutorial.

I am just going to the web portal on my local host, going to the data source option of the report, but it is impossible to change something when I select "Use the following credentials"( see below screen). what you don't see on the screen for some reason is that the cursor becomew a probibited sign when hovering over the field "user name" or "password".

I tried it in several browers (edge, IE, firefox and Chrome), but everywhere it is the same. I am logged on as administrator, so I would assume it is not a permission issue (altough the change in cursor makes me suspect otherwise).

I tried googling the subject for an hour or 2, but i didn't come across any useful information. As far as I can tell I configured the Reporting service correctly. I do notice that the first time I open the "Manage" menu of a report I only see the options "properties" and "security". When Inavigate back to the menu and try again I suddenly see all menu options like you see on the screenshot. I also often get the pop up "something went wrong, please try again later"

I am running windows 10 on my laptop and installed SQL server express 2017. I did read that SQL express does not support all features of the reporting services, could that be the root cause of the issue's?

I know this is quite vague, that is also what makes it hard for me to look it up... I hope someone else out there has encountered the same :)

Thanks for the input!

To answer my own question:

I was stupid enough to use SQL Express edition and this does not have all the features required to run SQL reporting services. After installing SQL developer edition all worked as it should.