Openlayers - set specific projection for View

How can I set a specific projection for a Map? I am using Openlayers 6 in an Angular 10 context.

The map is loaded in EPSG:3857 and I would like to use it via a projection EPSG:28992.

Try 1:

proj4.defs["EPSG:28992"] = "+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000  +ellps=bessel  +towgs84=565.040,49.910,465.840,-0.40939,0.35971,-1.86849,4.0772 +units=m +no_defs";
register(proj4)
let dutchProjection = GetProjection('EPSG:28992');

this.map = new Map({
  layers: [
    new Tile({
      source: new XYZ({
        url: 'https://geodata.nationaalgeoregister.nl/tiles/service/wmts/brtachtergrondkaart/EPSG:3857/{z}/{x}/{y}.png',
      })
    }), this.vectorLayer
  ],
  view: new View({
    projection: dutchProjection,
    center: [173563, 441818],
    zoom: 10
  }),
  target: "map"
});

Try-2:

let dutchProjection = new Projection({
  code: "EPSG:28992",
  units: "m",
  extent: [-285401.92, 22598.08, 595401.9199999999, 903401.9199999999]
});

this.map = new Map({
  layers: [
    new Tile({
      source: new XYZ({
        url: 'https://geodata.nationaalgeoregister.nl/tiles/service/wmts/brtachtergrondkaart/EPSG:3857/{z}/{x}/{y}.png',
      })
    }), this.vectorLayer
  ],
  view: new View({
    projection: dutchProjection,
    center: [173563, 441818],
    zoom: 10
  }),
  target: "map"
});

Inspired by the answers of @Mike, this solution works! Option 1 was correct but has an error.

proj4.defs("EPSG:28992","+proj=sterea +lat_0=52.15616055555555 +lon_0=5.38763888888889 +k=0.9999079 +x_0=155000 +y_0=463000  +ellps=bessel  +towgs84=565.040,49.910,465.840,-0.40939,0.35971,-1.86849,4.0772 +units=m +no_defs");