dotnet build TemplatePlugin.csproj -c Release
After building go into bin/release/net10.0 and find TemplatePlugin.dll
Of course if you changed the name, then look for the name of your plugin.
After finding it, put ONLY the TemplatePlugin.dll and manifest.json into a .zip named TemplatePlugin.zip, or whatever you named your plugin, then switch the file format to .kox via renaming and test it out!