Drag and Drop it

You can choose an element either by clicking on it on the canvas or in the layer list. Once a layer is selected, you will see a drag control. Click and hold your mouse and drag the element to the position you want.

While dragging, the layer will snap to the edges of the canvas and to the centerpoints of your canvas.

Use exact positioning

In the Arrange settings, you can set an exact position for your element.

Placid template editor - arrange panel