Get thumbnails with array sizes parameter

You’re almost correct.

You really can pass an array as size parameter for that function, but…

$size (string|array) (Optional) Image size to retrieve. Accepts any
valid image size, or an array of width and height values in pixels (in
that order). Default value: ‘thumbnail’

So you can’t use it in the way you wanted to…

You have to pass name of the size or an array that will define the size in pixels (width and height).

You can get only one size with one call of that function (as it returns only one value – url of image in given size).

But that’s not a problem, just call it twice:

$thumb_url = wp_get_attachment_image_url( get_the_ID(), 'thumbnail');
$full_url = wp_get_attachment_image_url( get_the_ID(), 'full');