Unable to use sudo privileges in terminal

I followed the instructions here to set up a tljh server on Jetstream. After getting it up and running, I was able to log in and access the admin panel to add and remove users. Following the instructions, I opened up the terminal to attempt to install some conda packages. Using the same password I used to log into the server, I am unable to get past the password prompt. I’ve tried shutting down and re-starting the server and have also tried adding other admin users, but I can’t seem to find a user/password combo that works. It appears that I can’t run any sudo commands.

Here’s an example of what I’m trying:

jupyter-karlwx@js-168-125:~$ sudo -E conda-install -c conda-forge cartopy
[sudo] password for jupyter-karlwx: 
Sorry, try again.
[sudo] password for jupyter-karlwx: 
sudo: 1 incorrect password attempt
jupyter-karlwx@js-168-125:~$ su
Password: 
su: Authentication failure

Any help and suggestions would be appreciated!