Save polygon or line to database django/mapbox - django

Question

I would like to save the drawn polygon in the code below to the postgis database :
Assume that mapbox is set correctly and that the polygon drawing and download works (i haven't put everything in the code to focus on the problem at hand)
<script type="text/javascript">
map.addControl(draw);
map.on('draw.create', updateArea);
map.on('draw.delete', updateArea);
map.on('draw.update', updateArea);
function updateArea(e) {
var data = draw.getAll();
var answer = document.getElementById('calculated-area');
if (data.features.length > 0) {
var area = turf.area(data);
// restrict to area to 2 decimal points
var rounded_area = Math.round(area*100)/100;
answer.innerHTML = '<p><strong>' + rounded_area + '</strong></p><p>square meters</p>';
var convertedData = 'text/json;charset=utf-8,' + encodeURIComponent(JSON.stringify(data));
document.getElementById('export').setAttribute('href', 'data:' + convertedData);
document.getElementById('export').setAttribute('download','data.geojson');
} else {
answer.innerHTML = '';
if (e.type !== 'draw.delete') alert("Use the draw tools to draw a polygon!");
}
}