<script>
    function q1() {
        // 1. Bring input-q1. $('# .... ').val()
        // 2. if(txt =='')
        // 3. alert('Type!')

        let txt = $('#input-q1').val()
        if (txt == ''){
            alert('Type!')
        } else {
            alert(txt)
        }
    }

    function q2() {
        // 1. Bring input-q2. $('# .... ').val()
        // 2. if there is @ (FYI: includes)
        // 3. info@gmail.com -> gmail (Using .split('@'))
        // 4. alert(domain);
        // 5. if not an email, alert with 'Not an email' 
        let txt = $('#input-q2').val()
        if(txt.includes('@') == true) {
            alert(txt.split('@')[1].split('.')[0])
        } else {
            alert('Not an email')
        }



    }

    function q3() {
        // 1. Bring input-q3. let txt = ... q1, q2
        // 2. let temp_html = `<li>${txt}</li>`)
        // 3. Append temp_html to names-q3.            ($('...').append(temp_html))
        let txt = $('#input-q3').val()
        let temp_html = `<li>${txt}</li>`
        $('#names-q3').append(temp_html)
    }

    function q3_remove() {
        // 1. Empty all tags in names-q3.($('....').empty())
        $('#names-q3').empty()
    }

</script>

FYI for making alerts .... for Q1!

Q1. Explained.

Q2. Explained.

Q3. Explained.