I don't think you can log in with a gemini browser (gemini can't maintain session state by design. I think you can use client certificates for maintining server-side state but whatever). You have to use the web interface for that.
By the way, it seems it's possible to post using a simple shell script. Please refer to
You could probably hack something together in elisp with
~bartender, some hydric acid for me please!
Howdy, I have tried the script mentioned in the manual, but failed. I could find the required cookie content, but something was amiss. So I would be interested, too, how to get this rolling.
~bartender? A lemonade please, it has been so hot today. Thanks!