Hi Tung Tran,
Thanks for contacting syncfusion support.
We can render our EJ2 Gantt control in php core platform, please find the sample below.
But at present there is no support for exporting the EJ2 Gantt(JavaScript based) to pdf or excel. We have already logged a feature report for this, please find the below feedback link to track its status.
We are currently working on this feature and it will be included in our upcoming Volume 3, 2019 main release, which is expected to be rolled out at the mid of October, 2019.
Regards,
Gurunathan