Popup with contact information for the mobile version?

Question

WordPress

Good afternoon, tell me which plugin to use for this view:

Answer 1

I won’t tell you the plugin, otherwise it’s just a block that is displayed at the screen size

@media screen and (max-width:768px) {
.bottom-block {
display:block;
}
}

Positioning the block

.bottom-block {
display:none;
position:absolute;
bottom:0;
}

<div class="bottom-block">
<!--Тут содержимое блока-->
</div>

Next, style for yourself.