How to log in to the Jerboa app?

Hi! I'm a new user. I was trying to log in to the Jerboa app as I find it to be the official app. While trying to log in, it is giving me these errors.

• Server version (0.17.4) too low.
• Server version (0.17.4) is under the minimum supported version (0.18). Please inform your administrator and login to another instance, or sign out and use the default instance.

Is there any way to log in to the official app using this server(lemm.ee)?