load-random-post.js

$( '.load-random-post' ).on( 'click', function( e ) {
	$.ajax( {
		url: themePostData.postsEndpointURL,
		data: {
			filter: {
				'posts_per_page': 1,
				'orderby': 'rand'
			},
		},
		dataType: 'json',
		type: 'GET',
		success: function( data ) {
			var postTitle = data[0]['title']['rendered'];
			var section   = $( '.post' );

			section.find( '.entry-title' ).hide().html( postTitle ).fadeIn( 'slow' );
		},
		cache: false
	} );
} );