You can simply show toast using data attributes.

on Page Load

<div class="toast"
    data-title="Hi, there!"
    data-message="Hope you like paper panel."
    data-type="success">
</div>

<button class="btn btn-primary btn-lg toast-action"
        data-title="Hey, Bro!"
        data-message="Paper Panel has toast as well."
        data-type="info"
        data-position-class="toast-bottom-right">
    Info Toast</button>

<button class="btn btn-primary btn-lg toast-action"
        data-title="Hey, Bro!"
        data-message="Paper Panel has toast as well."
        data-type="error"
        data-position-class="toast-bottom-left">
    Error Toast</button>

<button class="btn btn-success btn-lg toast-action"
        data-title="Hey, Bro!"
        data-message="Paper Panel has toast as well."
        data-type="success"
        data-position-class="toast-bottom-left">
    Success Toast</button>

<button class="btn btn-warning btn-lg toast-action"
        data-title="Hey, Bro!"
        data-message="Paper Panel has toast as well."
        data-type="warning"
        data-position-class="toast-bottom-left">
    Success Toast</button>