Renaming [ds-example]

What is the easiest way to rename dsexample plugin. For example:
I have:
[ds-example]
enable=0
processing-width=512
processing-height=512
full-frame=1
#batch-size for batch supported optimized plugin
batch-size=1
unique-id=15
gpu-id=0

I want :
[My-Name]
enable=0
processing-width=512
processing-height=512
full-frame=1
#batch-size for batch supported optimized plugin
batch-size=1
unique-id=15
gpu-id=0

You can modify it here,
sources/apps/apps-common/src/deepstream_config_file_parser.c:166:#define CONFIG_GROUP_DSEXAMPLE “ds-example”
and recompile the sample.

We have multiple custom gst-plugins. How to attach them all to the deepstream-app?

You need to be familiar with gstreamer first,
https://gstreamer.freedesktop.org/documentation/application-development/basics/elements.html?gi-language=c
and you may refer to any sample for how to add plugin and link them.
/opt/nvidia/deepstream/deepstream-5.0/sources/apps/sample_apps/