alert(1337)
on sandbox.pwnfunction.com
.https://sandbox.pwnfunction.com/?html=&js=&css=
.<!-- Challenge -->
<h2 id="maname"></h2>
<script>
let jeff = (new URL(location).searchParams.get('jeff') || "JEFFF")
let ma = ""
eval(`ma = "Ma name ${jeff}"`)
setTimeout(_ => {
maname.innerText = ma
}, 1000)
</script>