Hi Linh,

You can find Kalium Documentation on this URL http://documentation.laborator.co/item/kalium and specially Getting Started section.

Also please check if your server meets the recommended PHP configuration limits as follows:

• max_execution_time 180
• memory_limit 128M
• post_max_size 64M
• upload_max_filesize 64M
• max_input_time 60

For more info visit this link Recommended PHP Configuration Limits.

If you need more info, please don't hesitate to reply here :)