Wordpress require image alt and title workaround found on https://wpkraken.io/blog/wordpress-images/

functions.php

<?php

/* Automatically set the image Title, Alt-Text, Caption & Description upon upload
-----------------------------------------------------------------------*/

add_action('add_attachment', 'my_set_image_meta_upon_image_upload');

function my_set_image_meta_upon_image_upload($post_ID) {

  // Check if uploaded file is an image, else do nothing
  if (wp_attachment_is_image($post_ID)) {

    $my_image_title = get_post($post_ID)->post_title;

    // Sanitize the title: remove hyphens, underscores & extra
    // spaces:
    $my_image_title = preg_replace('%\s*[-_\s]+\s*%', ' ', $my_image_title);

    // Sanitize the title: capitalize first letter of every word
    // (other letters lower case):
    $my_image_title = ucwords(strtolower($my_image_title));

    // Create an array with the image meta (Title, Caption,
    // Description) to be updated
    // Note: comment out the Excerpt/Caption or Content/Description
    // lines if not needed
    $my_image_meta = [
      // Specify the image (ID) to be updated
      'ID'           => $post_ID,
      // Set image Title to sanitized title
      'post_title'   => $my_image_title,
      // Set image Caption (Excerpt) to sanitized title
      'post_excerpt' => $my_image_title,
      // Set image Description (Content) to sanitized title
      'post_content' => $my_image_title,
    ];

    // Set the image Alt-Text
    update_post_meta($post_ID, '_wp_attachment_image_alt', $my_image_title);

    // Set the image meta (e.g. Title, Excerpt, Content)
    wp_update_post($my_image_meta);
  }
}