Hi @ozgur_agi,
There is no easy way to achieve this. Radzen templates (generated meta) are .NET version dependent and some components have different features/settings. Also security tables are different between .NET versions - you might have problems if you have default security (.NET Identity) enabled.
Still, you can try the following If you do not have any custom code in the /server folder and default security:
- Delete the entire /server folder
- Change serverVersion from 3 to 6 in meta/app.json
- Run the application from Radzen.