datePicker problem initialisation

I need to set on my input a datepicker ( i'm free user )

I have an error in the console : " Uncaught TypeError: $(...).datepicker is not a function "

I've seen the difference between MDB Versions and i have to use the datepicker function with the version 4.19.1

I use CDN for call the MDB libraryI've tried to download the library and use it locally but same issue.

Here is my code, I really don't understand what's wrong i need help : (i use the basic input html )

<!-- JQuery -->
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<!-- Bootstrap tooltips -->
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.4/umd/popper.min.js"></script>
<!-- Bootstrap core JavaScript -->
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.5.0/js/bootstrap.min.js"></script>
<!-- MDB core JavaScript -->
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/mdbootstrap/4.19.1/js/mdb.min.js"></script>

<script type="text/javascript">
    // Data Picker Initialization
    $('.datepicker').datepicker();
</script>