@apply cannot be used when with pseudo-class like :hover, :active, etc.

[Olshansk]

I found @adamwathan's answer here which discusses and resolves the error above: tailwindlabs/discuss#71 (comment)

However, the text quoted in the answer was removed from https://tailwindcss.com/docs/functions-and-directives#apply.

Further, one of the example on the page above uses hover along with the @apply directive like so:

.btn-blue {
  @apply bg-blue-500 hover:bg-blue-700 text-white;
}

I'm not sure if I'm missing something or if this example is incorrect?