Create debian package from source

Hello everyone. My name is Max and my profession is DevOps. I'm working in company which use Elastic Stack. New security standards for our product require building your software from source code and creating deb packages. I have some experience in packaging software but I really can't understand how do it with logstash (kibana and elasticsearch).
http://salsa.debian.org have no repository with version of 6.6.1 that we need
Can anybody help me to found documentation, debian instructions (archives ..debian.tar.gz) and etc?

You can just follow the logstash guidelines here GitHub - elastic/logstash: Logstash - transport and process your logs, events, or other data

Yes, I've seen this documentation, but it would be better if someone could tell me where the logstash_6.6.1.debian.tar.gz archives are located, because our CI / CD pipeline uses the standard debuild utility to create packages. What you posted demonstrates how to build a package with custom Elastic Stack instructions from a developer, this is not what I need at all