Ask HN: How to attract beta users for my productivity SaaS?

I started as a side project, and after 6 months of development, I feel my baby is ready for some beta users. Coming from an engineering background, I had no experience in marketing. I am not looking for a large number of users, only maybe 100 for testing and feedback purposes.

I started with the idea of managing all contents and tools better (into a single contextual workspace). Here is the website for more details: https://www.superusapp.com/