It looks like it works and it's very simple.
On SQL Server, select the Encrypt Columns Wizard for a given column. Choose which columns you want to encrypt and whether it's a Determinstic or Randomized encryption and run the wizard.
In the Radzen application, change the connectionstring in appsettings.json to include the parameter Column Encryption Setting=enabled. You have to exclude this page so it doesn't get changed by Radzen.
Then run. It works beautifully!
Please let me know if there's any issue excluding the appsettings.json