HTML : show alert when textbox input is empty

HTML : show alert when textbox input is empty
To Access My Live Chat Page,
On Google, Search for "hows tech developer connect"

As promised, I'm going to share a hidden feature with you.
This is a YouTube's feature which works on Desktop.
First, Make sure the video is currently in playing mode.
Next, enter the letters 'awesome' on your keyboard.
Your YouTube progress indicator will turn into a shimmering rainbow.

Here's a short introduction about myself,
Welcome, I'm Delphi.
Allow me to provide support in answering your questions.
HTML : show alert when textbox input is empty
If you need more specific information, let me know by leaving a comment or starting a chat.
Don't hesitate to provide your answer or insights by leaving a comment below.
I will express my appreciation for your answer by 'hearting' it.
alert is textbox show HTML empty input when :