The codes are already in the module and you should check it from /modules/mod_easysocial_dropdown_menu/tmpl/default.php

Thanks Mark, i can find the part of the code that show the greeting but i get error on frontend !

<div class="o-media">

				<div class="o-media__image">

					<?php echo $lib->html('avatar.user', $lib->my, 'default', true, true, '', false); ?>

				</div>

				<div class="o-media__body t-text--left mod-es-dropdown-menu__body">

					<span class="mod-es-dropdown-menu__name">

					<?php echo JText::_('MOD_EASYSOCIAL_DROPDOWN_MENU_HI');?>, <b><?php echo $lib->my->getName();?></b></span> <i class="i-chevron i-chevron--down t-lg-ml--sm t-lg-mt--sm"></i>

				</div>

			</div>

i add this to a custom module,
i made some thing wrong !?

You cannot just blindly copy the code and expect it to work. If you are trying to use the $lib, you need to define $lib first. Please look at /modules/mod_easysocial_dropdown_menu/mod_easysocial_dropdown_menu.php