Is this valid fitting tag button between fieldset?

Is this a semantically clean?

<form>
    <fieldset>
        <input type="text">
        <button>Send it</Button>
    </fieldset>
</form>

Or this?

<form>
    <fieldset>
        <input type="text">
    </fieldset>
    <button>Send it</Button>
</form>

Or both variants are correct?