How to make it suit for Ubuntu20.04 and gazebo 11?

[Dy-314]

Thanks for your excellent working in the livox simulation program.
When I am running the demo in ubuntu20.04 with gazebo 11, it return errors as follow.
Error [parser_urdf.cc:3183] Unable to call parseURDF on robot model
Error [parser.cc:488] parse as old deprecated model file failed.
[Err] [World.cc:2199] Unable to read sdf string[<Livox_Avia downsample="1" name="livox" publish_pointcloud_type="3" visualize="true" />19.8Gazebo/White]
Appreciate for any of your replies.
Best wishes.