I’d suggest that you post the “hello world” sketch that worked, and if possible post a link to the LCD library that you’re using.
As I said earlier, each library has its own set of commands, and without understanding what your library requires it’s impossible to know if anything is missing from your code.
I have successfully used this LCD library with past Blynk projects and same (as OP code above) Widget to LCD commands, although I used Terminal at the time.
@Syed_Fitri 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:
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You still haven’t fixed the formatting of your “hello world” code.
It will be deleted soon if you don’t fix it, as will other Unformatted code that you post in future.
We give people the benefit of the doubt when that don’t follow the instructions about posting code that glare provided when they creat a new topic, and two of us have asked you to fix the code formatting but you haven’t.
It’s a simple rule of the forum that you need to follow.
You had a go at editing the code, but I’m sure you could tell that it wasn’t formatted correctly, so I’ve deleted it.
If you wish to repost it then simply edit the post and paste the code in between triple backticks, but without any other formatting characters.
However, @Bill_Donnelly has already pointed-out why the ‘hello world’ sketch worked and your Blynk sketch doesn’t, so you know the answer to your problem.