I am looking to have a canvas with an output of 562mm x 642mm and customers can upload their logos, text and graphics.
I check via a dpi online calculator converter and the px size is 7583 x 6638.
How would I set this up?
Just set the dimensions you've calculated as stage size. As the front-end is responsive it will automatically scale to fit. In the backend there are buttons in the product builder to scale the stage.