But for the price of ngrok I'm paying for a domain and a 2gb ram/2 CPU VM on hetzner and using SSH tunnels to nginx reverse proxy.
And setting up a shared server for a team with subdomains is just 10 mins of config changes per user - no way they can justify the cost for me.
If it was some symbolic price like 20$/year then I wouldn't bother, otherwise I'll take the VM I can load other random dev crap to when I need it.
And you're using standard web tech to set this up - if you aren't familiar with something required to set this up you will be better off learning it in the long run (if you're the target audience for ngrok) : VM setup, nginx, reverse proxy, SSH tunneling, let's encrypt, domain management/DNS - all valuable fundamental skills to acquire on a small project.