Simple steps for using animate.css

you need reference to animate.css . You can download the file from
Animate css repository

CSS class
In this example below I am using bounceIn and flipInx feature

.ng-hide-remove {
    -webkit-animation: bounceIn 2.5s;
    animation: bounceIn 2.5s;
}
 
.ng-hide-add {
    -webkit-animation: flipInX 2.5s;
    animation: flipInX 2.5s;
    display: block !important;

Reference the CSS class
Now you can use the css class in your html file 

 <div class="ng-hide-add">
                        There are
                        <label class="error-duplicate">
                            ({{DuplicateInFile.length}}
                            <i class="fa fa-file-text fa-lg" aria-hidden="true"></i><span class="error-duplicate"></span> )
                        </label>
                        in file duplicates and
                        <label class="error-duplicate">
                            ({{DuplicateInDb.length}}
                            <i class="fa fa-database fa-lg" aria-hidden="true"></i><span class="error-duplicate"></span> )
                        </label>
                        in DB duplicates of ({{Registrations.length}}) discrepancies
                    </div>

You can find the different animation options at this site
https://daneden.github.io/animate.css/

Note: For change in animation we need to specify the class name and time taken for the animations

animation: bounceIn 2.5s;

You can find more options online