How to align an image to the center of the document in Photoshop and set its size?

Question

Adobe Photoshop

I'm doing a Photoshop action and I want to insert a picture, give it a size of 2.5cm and its position to be 150y and 150x or in the center of the document.

• Alignment is not done in the center of the document, but on a larger layer. It is impossible to align on the key layer as in a chandelier. I set the position in pixels to 150y and 150x, it records in actions as a shift of -1.12cm and -1.19cm. And if the next picture is smaller or larger, then with this shift, it will be off-center.
  
• I set the size of the picture to 2.5 cm, the width of the action is 52%, the height is 52%. I have pictures of different sizes and they will no longer be 2.5 cm.