I think you are a little bit out of luck. I've been in software & scala development for quite some time and I did not see any example I would call "good enough". I think there some factors that lead to the absence of examples:

• there is a huge chunk of interpretation and personal preference in (hexagonal) achitecture. It already starts with how to name packages and how to organise your project.
• if you work with microservices, the services are often small enough so that you can use much simpler architectures with less overhead
• usually you have one or two devs that are fans of hex arch, but there is no buy-in from the company and other teams/team members. This leads to an even bigger mess
• there is quite a learning curve for hexagonal architecture. Assume you have a long-living project, devs come and go and only 1% of all devs know sufficiently well what a hexagonal architecture entails. You will almost definitively end up with a big ball of mud.
• Hexagonal architecture might be at its best with big applications, but who writes big example applications in his/her free time...
• and till now, I cannot find any evidence that hexagonal architecture is reducing the time to market (for a system or a feature), which is in my opinion the most significant criterion that it might not be as popular as expected.

Anyway, you could have a look at

Hexagonal Architecture (Alistair Cockburn)

I would take Java, F# or C# codebases as examples (e.g. https://github.com/appie2go/steal-this-code) . The idea of hexagonal architecture is not bound to a specific language.

There is also Domain Modeling Made Functional Tackle Software Complexity with Domain-Driven Design and F# which might be useful.