How can I successfully SSH into my Ubuntu 20.04 server after password stopped work?

I have a Raspberry Pi that is running Ubuntu and it has been working fine until I tried updating the WiFi network name and password (sudoedit /etc/netplan/50-cloud-init.yaml). After doing so, I was no longer able to SSH into the server, but my scheduled scripts are still running, so the server seems to be operating normally, all considered. It’s like my username/password combination just stopped working.

Does anyone know how I might be able to reset the ubuntu password or if there is another way of logging in? I should mention that this is a “headless” setup and that I have installed xrdp which allows me to ‘rdp’ into the server; it still works but the user/password combination does not.

Please let me know if there is anything else I can provide for you so that I can be successful in finding a solution.