Rotating an object to mirror it on a given line in pixi 8

[ApricotMimosa]

I want to write a function that mirrors an object on a line given by two points. In the example, the object is an rectangle. I know, I can achieve horizontal and vertical mirroring using .scale but I want to be more flexible. My idea is to set the pivot point to the point on the line (red in the example) that creates an orthogonal line when connected with the center of the object (green in the example). A rotation by 180° degrees should than archieve the mirroring but it does not.

// Create a Pixi Application
const app = new PIXI.Application({ width: 800, height: 600 });

// Create a first rectangle
const rect = new PIXI.Graphics();
rect.beginFill("white"); // Red color
rect.drawRect(-50, -50, 100, 100);
rect.endFill();
rect.x = 200;
rect.y = 200;

app.stage.addChild(rect);

// define mirror line
const p1_arr = [380,0]
const p2_arr = [400,600]

mir = new PIXI.Graphics();
mir.lineStyle(2, "white", 1.0); 

mir.moveTo(p1_arr[0], p1_arr[1]);
mir.lineTo(p2_arr[0], p2_arr[1]);

app.stage.addChild(mir);

// equation for line crossing the two points
const slMirAx_fl = (p2_arr[1] - p1_arr[1]) / (p2_arr[0] - p1_arr[0]);
const yMirAx_fl = p2_arr[1] - p2_arr[0] * slMirAx_fl;

// get center of child
const cent_arr = [rect.x, rect.y];

const centerPoint = new PIXI.Graphics();
centerPoint.beginFill("green");
centerPoint.drawCircle(cent_arr[0], cent_arr[1], 5);
centerPoint.endFill();
app.stage.addChild(centerPoint);

// compute intersection of center and orthogonal point
const yRec_fl =  cent_arr[1] - cent_arr[0] * (-1 / slMirAx_fl);
const intSectX_fl = (yRec_fl - yMirAx_fl) /  (slMirAx_fl + 1/slMirAx_fl)
const intSecY_fl = yMirAx_fl + intSectX_fl * slMirAx_fl

const pivotPoint = new PIXI.Graphics();
pivotPoint.beginFill("red");
pivotPoint.drawCircle(intSectX_fl, intSecY_fl, 5);
pivotPoint.endFill();
app.stage.addChild(pivotPoint);

// Add the renderer view to the DOM
document.body.appendChild(app.view);

// Render the stage
app.renderer.render(app.stage);


setInterval(() => {

  // set intersection as pivot point and rotate by 180 degrees
  const oldPivot_dic = rect.pivot
  rect.pivot = {x: intSectX_fl, y: intSecY_fl}
  rect.rotation = Math.PI;

  // reset pivot
  rect.pivot = oldPivot_dic

  app.renderer.render(app.stage);
}, 5000);