How to force laravel validate to validate a field only if it is not empty?

Question

Laravel

There is a field to which I gave validation parameters: url | max:40 . The field is optional and may be empty. But in this case, I constantly get an error that the field does not fit the url format. Well, it's clear, it's empty. So how to explain to Lara that validation should be done only if the field is filled?

Answer 1

Add sometimes and nullable rules.
sometimes|nullable|url|max:40

Answer 2

So have you tried it?
url | min:0 | max:40