Images could be added to mapbox using a Layer and Source.

Layer configuration

Prepare a source configuration by referenceing (this document)[https://docs.mapbox.com/mapbox-gl-js/style-spec/#sources-image]

const Image_SOURCE_OPTIONS = {
    "type": "image",
    "url": "https://docs.mapbox.com/mapbox-gl-js/assets/radar.gif",
    "coordinates": [
        [-80.425, 46.437],
        [-71.516, 46.437],
        [-71.516, 37.936],
        [-80.425, 37.936]
    ] 
};

For base64 image, the url could be data:image/png;base64, + base64 image data:

const Image_SOURCE_OPTIONS = {
    "type": "image",
    "url": "data:image/png;base64,...",
    "coordinates": [
        [-80.425, 46.437],
        [-71.516, 46.437],
        [-71.516, 37.936],
        [-80.425, 37.936]
    ] 
};

Create a Source

<Source id="source_id" tileJsonSource={RASTER_SOURCE_OPTIONS} />

Create a Layer

Reference (react-mapbox-gl document)[https://github.com/alex3165/react-mapbox-gl/blob/master/docs/API.md#layer], the type could only be symbol, line, raster, ...

 <Layer type="raster" id="layer_id" sourceId="source_id" />