inp.value=inp.value.replace(/[^\.0-9]/gim,'');
input.value = parseFloat(e.target.value).toFixed(2);const pos = e.target.selectionStart; // запомнить положение курсора
// magic
e.target.selectionStart = e.target.selectionEnd = pos; // восстановитьconst pos = e.target.selectionStart;
let v = parseFloat(e.target.value);
if( isNaN(v)) v = 0;
e.target.value = v.toFixed(2)
e.target.selectionStart = e.target.selectionEnd = pos;
<input type="number" step="0.01" value="1.00">document.querySelector("input").addEventListener("input", function() {
this.value = parseFloat(this.value).toFixed(2);
});