How to set focus on element programmatically?

[elibroftw]

<TextBox Name="OtpTextBox" Visibility="{x:Bind OtpInputVisible}" utu:AutoLayout.CounterAlignment="Center" Width="328" PlaceholderText="OTP" Style="{StaticResource OutlinedTextBoxStyle}">
                <um:ControlExtensions.Icon>
                    <PathIcon Data="{StaticResource Icon_Shield}" />
                </um:ControlExtensions.Icon>
            </TextBox>

public async void TryLogin(object sender, RoutedEventArgs e) {
//  set focus on the element shown above... OtpTextBox is currently undefined.
}

[elibroftw]

Name's can be referenced as variables in the business logic without having to declare them.

OtpTextBox.Focus(FocusState.Keyboard);