Filebeat process different log paths and write data to seperate index,Without use of logstash and follow ILM/rollover alias defined in template

Elastic Stack Beats
5

You need to follow these directions

You will need to set up everything in with the templates and create an initial managed index for each

Look at method #2 here then generalized for your use cases with

index: "%{[fields.index]}-%{[agent.version]}"

You could also just set the index in each input see here:

filebeat.inputs:
- type: log
  enabled: true
  index: "mis-monitoring-usecases-{[agent.version]}"
...

- type: log
  enabled: true
  paths:
  - /l/app/LOG_ROOT/Demo/*.log
  index: "mis-logs-{[agent.version]}"

This is in the wrong place

filebeat.config.modules:
  path: ${path.config}/modules.d/*.yml

not sure why it is in the middle of your inputs ... if you use no modules you can take it out.
In fact not sure how that is working that should break things

You really need to get off 7.9.1 ... whatever the reason you are staying on it, does not outweigh the benefits of being on a newer version.