temp/Views/ConfigWindow.axaml

<UserControl xmlns="https://github.com/avaloniaui"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:vm="using:app.ViewModels"
             x:DataType="vm:MainWindowViewModel"
             x:Class="app.Views.ConfigWindow">
   <StackPanel VerticalAlignment="Center" HorizontalAlignment="Center">
        <TextBlock Text="Configure your application!" HorizontalAlignment="Center" VerticalAlignment="Center"/>
        <Grid ShowGridLines="False" Margin="5" ColumnDefinitions="Auto, Auto" RowDefinitions="Auto, Auto, Auto, Auto">
            <Label Grid.Row="0" Grid.Column="0">API Key:</Label>
            <TextBox Grid.Row="0" Grid.Column="1" Text="{Binding ApiKey, Mode=TwoWay}"/>
            <Label Grid.Row="1" Grid.Column="0">Speak Model</Label>
            <ComboBox Grid.Row="1" Grid.Column="1" SelectedItem="{Binding SpeakModel, Mode=TwoWay}" ItemsSource="{Binding SpeakModels}">
            </ComboBox>
            <Label Grid.Row="2" Grid.Column="0">Listen Model:</Label>
            <ComboBox Grid.Row="2" Grid.Column="1" SelectedIndex="0" SelectedItem="{Binding ListenModel, Mode=TwoWay}" ItemsSource="{Binding ListenModels}">
            </ComboBox>
            <Label Grid.Row="3" Grid.Column="0">Think Model:</Label>
            <ComboBox Grid.Row="3" Grid.Column="1" SelectedIndex="0" SelectedItem="{Binding ThinkModel, Mode=TwoWay}" ItemsSource="{Binding ThinkModels}">
            </ComboBox>
        </Grid>
        <Grid ShowGridLines="False" Margin="5" ColumnDefinitions="Auto, Auto" RowDefinitions="Auto">
            <Button Grid.Row="0" Grid.Column="0" CornerRadius="10" Background="Blue" Command="{Binding SaveConfig}">Save</Button>
            <Button Grid.Row="0" Grid.Column="1" CornerRadius="10" Foreground="Black" Background="Yellow" Command="{Binding CancelConfig}" IsVisible="{Binding ApiKey}">Cancel</Button>
        </Grid>
    </StackPanel>
</UserControl>