what is the code to invalid the entering of "sign-in" without typing password?

Question

<label><b>Password</b></label><br/>
<input type="password" name="password" placeholder="Enter password">
<input type="submit" name="submit" value="Sign-in">

#HTML only

Answer 1

Give the input a required attribute

<input type="password" name="password" placeholder="Enter password" required>

https://developer.mozilla.org/en-US/docs/Web/HTML/Attributes/required