logo and image are missing from AMP page

I found the answer:

for the logo, just upload a logo image in appearance -> customize

for the missing image, I had old posts with images inside but not “attached” the wordpress way.

So I had to change the pluging code to support it.

For anyone who’s interested:

in plugins/amp/includes/class-amp-post-template.php

	private function get_post_image_metadata() {
		$post_image_meta = null;
		$post_image_id = false;

		if ( has_post_thumbnail( $this->ID ) ) {
			$post_image_id = get_post_thumbnail_id( $this->ID );
		} else {
			$attached_image_ids = get_posts( array(
				'post_parent' => $this->ID,
				'post_type' => 'attachment',
				'post_mime_type' => 'image',
				'posts_per_page' => 1,
				'orderby' => 'menu_order',
				'order' => 'ASC',
				'fields' => 'ids',
				'suppress_filters' => false,
			) );

			if ( ! empty( $attached_image_ids ) ) {
				$post_image_id = array_shift( $attached_image_ids );
			}
		}

		if ( ! $post_image_id ) {       // get image from inside the post
            $image_url = (string) reset(simplexml_import_dom(DOMDocument::loadHTML($this->post->post_content))->xpath("//img/@src"));
            if (!empty($image_url)) {
                list($image_width, $image_height) = getimagesize($image_url);
                if ($image_width && $image_height) {
                    if ($image_width < 696) {       // google require minimum width of 696  https://developers.google.com/search/docs/data-types/articles
                        $image_width = 696;
                        $image_height = intval($image_height * 696 / $image_width);
                    }
                    $post_image_meta = array(
                        '@type' => 'ImageObject',
                        'url' => $image_url,
                        'width' => $image_width,
                        'height' => $image_height,
                    );
                }
            } else {
                $post_image_meta = array(
                    '@type' => 'ImageObject',
                    'url' => 'https://www.your domain.co.il/sample-photo.jpg',
                    'width' => 960,
                    'height' => 720,
                );
            }
		}

		if (!$post_image_meta) {
            $post_image_src = wp_get_attachment_image_src($post_image_id, 'full');

            if (is_array($post_image_src)) {
                $post_image_meta = array(
                    '@type' => 'ImageObject',
                    'url' => $post_image_src[0],
                    'width' => $post_image_src[1],
                    'height' => $post_image_src[2],
                );
            }
        }

		return $post_image_meta;
	}