Ok, I’ve checked your site and tried to install the demo but I always get a 500 Internal Server Error. This is usually from your hosting and it means you need to make some changes in the php.ini file. Also, increase the maximum memory allocated to php.
Here are the changes you need to make:
post_max_size 32M
upload_max_filesize 16M
max_file_uploads 32M
max_input_vars 5000
Also, check this too: https://codex.wordpress.org/Editing_wp-config.php#Increasing_memory_allocated_to_PHP
Let me know how’s going.
Cheers!