Hello there, this was a little problematic for a new elixir/phoenix user, but I got it to work, and I wanted to post this so someone might find value in my solution.
<body>
<!--
materialize appends the dom node to the body element so this script tag needs to be nested here
-->
<script phx-update="ignore"> <!-- The phx_update attribute is amazing <3 -->
let info = '<%= get_flash(@conn, :info) %>';
let error = '';
if(info){
M.toast({ html: info });
}
</script>