HTML Guide for submit
The button role is used to make an element appear as a button control to a screen reader and can be applied to otherwise non-interactive elements like <div>. If you’re already using an <input> element whose type is submit, then it’s redundant to apply it the role button, as that’s implicit.
<!-- Instead of this -->
<input type="submit" role="button">Buy</button>
<!-- Do this -->
<input type="submit">Buy</button>