input[type="radio"]:checked code example
Example 1: html radio button checked
<input type="radio" id="huey" name="drone" value="huey"
checked>
<!-- https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/radio-->
Example 2: radio input value
<input type="radio" name="test" id="test" value="this is the value">