Making checkboxes required when a check box is clicked [duplicate]

I have two check boxes that behave like radio buttons. Below is the code:

<form>

    <input type="checkbox" id="FirstBox" onclick="clickMe(this)" />Is this the first time, you are visiting this web site.
    <input type="checkbox" name="test" id="SecondBox"  onclick="interest(this) />Yes
    <input type="checkbox" id="ThirdBox" name="test"  onclick="interest(this) />No
  
    <button type="submit">Submit</button>
</form>

If the checkBox with id firstbox is clicked then user is required to click on either SecondBox or ThirdBox. SecondBox and ThirdBox
are behaving like a radio button with below code:

function interest(checkbox){

            var checkboxes = document.getElementsByName('test')
            checkboxes.forEach((item) => {
                if (item !== checkbox) item.checked = false
            })

            }

I want a required message to display when the user does not click on either Second or third checkbox. Below is what I tried to write:

function clickMe(fb)
    {
        var sb = document.getElementById("SecondBox");
        var tb = document.getElementById("ThirdBox");
        if(fb.checked == true{

            if (sb.checked == false && tb.ariaChecked == false)
            {
                Message saying that one of the check box is required right under the checkboxes.

            }
        }

    }

below is the screenshot:

any help will be appreciated.