The last parameter of add_submenu_page
expects a function callback, not a file include – hence the error as that is not a valid callback. (See add_submenu_page in the codex.) You can include the file in the function if you prefer:
add_submenu_page(
"???",
"Add / Edit Price Options in Kilometers",
"Add / Edit Price Options in Kilometers",
"manage_options",
"crsc-add-kilometers",
"add_edit_kilometers"
);
function add_edit_kilometers() {
include( 'admin/template.add-edit-kilometers.php' );
}
Also, the first parameter needs to be the parent slug menu ID you are adding the submenu to for this to work, you would need to replace ???
above.