[SOLVED] Validate Input : Missing attribute 'validate'

Do I miss anything here? My validate is not working. I want my input validate value on keypress or change.

It is unknown attribute but it is a flag for F7 to enable validation. Need an example or JSFiddle with the issue so i can see it

It’s ok now, I inserted this class surround <input> tag then it work

<div class="item-content item-input">
                                <input type="text" class="input-c-2 left" placeholder="Họ Đệm và Tên" id="fullName"
                                       required validate pattern="[A-Z a-z]{1,}" data-error-message="Nhập sai định dạng!" maxlength="28">