You can get the value with JavaScript with :

document.querySelector('input[name="programming"]:checked').value

<input type="radio" name="programming" id="" value="HTML">HTML</input>
<input type="radio" name="programming" id="" value="C++">C++ </input>
<input type="radio" name="programming" id="" value="JavaScript">JavaScript </input>
<input type="radio" name="programming" id="" value="Python">Python</input>
<button type="submit" id="submitBtn" class="submit">check</button>

<script>
    document.getElementById('submitBtn').onclick = function(){
       let val = document.querySelector('input[name="programming"]:checked').value; 
       console.log('Choosen: ', val)
    }
</script>

Try this code :

const btnSubmit = document.querySelectorAll('input[type="submit"]');

btnSubmit.addEventListener('click', e => {
    let checkedInputValue = document.querySelectorAll('input[name="programming"]:checked').value;
    console.log(checkedInputValue);

});