polygon.js | tessellation of concave polygons with holes in Javascript | 3D Animation library

In OpenLayers 5.3.0, I've created a MultiPolygon using the 'difference' tool in turf.js. The turf.js MultiPolygon looks fine when I examine the JSON, but when I try to use that to create a feature in OpenLayers, I get "Uncaught TypeError: t.addEventListener is not a function".

I've tried many combinations of JSON.stringify, JSON.parse, GeoJSON.readFeatures, .getCoordinates()... I tried adding the turf.js MultiPolygon as a feature directly via source.addFeature(multiPolygonGeometry), but then I get 'Uncaught TypeError: e.getId is not a function'. I also tried source.addFeatures(multiPolygonGeometry) (note the plural 'addFeatures'), and that didn't give me any errors, but also didn't appear to add anything to the source.

Relevant lines in my code are as follows:

I am embarrassed by how elementary this problem seems, but I can't seem to work out how to simply add a GeoJSON polygon feature to a vector source.

I'm using OpenLayers 5, and up until now I've been creating a separate source and layer for every feature I'm adding to the map. The reason being I needed to be able to turn the visibility of individual polygons on and off, and this seemed like the best way to do that at the time. This worked at first, but I'm sure it's not the best practice - in effect I'm creating 200 layers and 200 sources for 200 polygons. I'd prefer to be creating one layer which uses one source which contains those 200 polygons.

This is what I currently have:

I'm using Google Map with React. But when I run my project, I get an error in Polygon.js file

TypeError: Cannot read property 'Component' of undefined

TypeError: Cannot read property 'array' of undefined

Please, let me know why?

This is snip code and image description for error: