The people who run Terrarium read every message, and replies go to the email address on your account.
Send feedback from your dashboard
Press Send feedback at the bottom of your dashboard, write your message and press Send. Terrarium includes your username and the page you were on, so you don't need to explain which account it's about.
Let the help assistant write it
If you're already asking the help assistant, ask it to tell the team. It writes a draft under its answer with Send and Edit buttons. Nothing goes until you press Send. Edit opens the same form as Send feedback, with the draft filled in, so you can change it first.
You can also email support@getterrarium.app.