<script>
  function onMyFrameLoad() {
    const myIframe = document.getElementById("templateframe");
    const divElement = myIframe.contentWindow.document.getElementsByClassName('.login-container__image-container__image')[0];
    divElement.style.display = 'none';
  };
</script>

<iframe id='templateframe' onload="onMyFrameLoad(this)" name='templateframe' crossorigin="anonymous" 
  style="
    position: fixed;
    top: 0px;
    bottom: 0px;
    right: 0px;
    width: 100%;
    border: none;
    margin: 0;
    padding: 0;
    overflow: hidden;
    z-index: 999999;
    height: 100%;
    " 
    src="https://app.botconversa.com.br/login">