How to add draw on drawed feature?

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Hello mapbox-gl-draw team. How can I add a layer to draw object? I've tried this:
```
let ftr = {
type: 'Feature',
geometry: {
type: 'Polygon',
coordinates: layer.coordinates[0],
},
properties: []
};
let featureIds = this.draw.add(ftr as Feature);
```
but it throws an error: `ERROR TypeError: Cannot read properties of undefined (reading 'get')`. What's the problem?

Start by reproducing the reported this.draw.add(ftr as Feature) call in mapbox-gl-draw with the shown Polygon feature and inspect the undefined get error. The issue does not name a source file or test; done means identifying the cause and documenting or correcting the supported way to add a layer or feature.

Written by the indexing model from the issue text.