JSFiddle - React, Tailwind, and code Playground

HTML

<input type="number" name="quantity" min="-15000" max="5000">

JavaScript

var elm = document.getElementsByName('quantity')[0];
elm.addEventListener('focusout', function() {
    var num = Number(elm.value);
		if (num > 0 && num < 1000) {
    		elm.value = '';
        alert('Neplatna hodnota');
    }
});