User665608656 posted
Hi danik,
now I don't not is there any possibilities to design my application on MacOS?
According to your description, I checked the questions in the Visual Studio for Mac community.
I'm sorry to tell you that there is no visual designer and empty toolbox for ASP.NET project in the Mac version of Visual Studio.
This is the relevant information for discussion in the community:
No Design View Visual Studio 2017
Toolbox empty & Design view does not work for ASP.NET projects
So, it is recommended that you use windows version of VS for operation.
Best Regards,
YongQing.