#error "Please specify your BLYNK_TEMPLATE_ID and BLYNK_TEMPLATE_NAME"

[Unformatted compiler error message removed by moderator]

the error is

[Unformatted compiler error message removed by moderator]

@rafifaza888 Please edit your post, using the pencil icon at the bottom, and add triple backticks at the beginning and end of your code so that it displays correctly.
Triple backticks look like this:
```

Copy and paste these if you can’t find the correct symbol on your keyboard.

Please also do the same for your compiler error message.

Pete.

@rafifaza888 your unformatted code and compiler error message have been removed because you didn’t fix the formatting as requested.

I’d suggest that you read this link to help you resolve your compiler issue…

But, your code has a serious flaw which will result in your sketch flooding the Blynk server with data.

You MUST remove this line of code from your void loop before re-compiling and uploading the sketch to your device…

ultrasonic();

You should read this article about calling the code in your ultrasonic() with a BlynkTimer instead…