I think this is not the best solution because I had to customize the core file of Easy Admin rather than extends.
- Need to add footer block \vendor\easycorp\easyadmin-bundle\src\Resources\views\default\layout.html.twig
{% endblock wrapper %}
</div>
<div class="wrapper">
{% block footer %}
{% endblock footer %}
</div>
2. Need to extend the layout twig of Easy admin
templates\bundles\EasyAdminBundle\default\ layout.html.twig
{# templates/bundles/EasyAdminBundle/default/layout.html.twig #}
{% extends '@!EasyAdmin/default/layout.html.twig' %}
{% block footer %}
<div></div>
<div class="copy-right">
<h4> copyright@2020, ST Actions </h4>
</div>
{% endblock %}