Width height value for images

[Alpacala]

Hello friends, I'm writing here since the topic is related to SEO. When I examined my page on Google Pagespeed tests, it says that the image does not have explicitly specified width and height values. In terms of SEO compatibility, should images in responsive designs have width and height values in pixels? Typically, they are given as a percentage based on the screen size. If it needs to be specified, for example, if the image is 1000 X 1000 but we want it to appear as 400 X 400 on the page, should it be set to 1000 X 1000 or 400 X 400?