Why is JavaScript being added to header as application/oembed?
The oEmbed discovery link tags are added by core in wp_oembed_add_discovery_links() since version 4.4. See the changeset here. When we enqueue scripts in the footer, we have to make sure the wp_footer() is not missing. There was a typo in the enqueued script here, since the HTML select tag had id=”txt2give” but not id=”text2give”.