Can't login to droplet with SSH and access console is unresponsive

I created a droplet and added my SSH key in the creation process. It worked well, I could easily connect to server from my local machine via SSH.

Later I created a new SSH key in my local machine, I uploaded it to the DO control panel. But as I understand that key is not automatically transferred to droplet if the droplet was already created, right?

So now I can’t login via SSH - Permission denied (publickey).

I opened the tutorial “How to Upload an SSH Public Key to an Existing Droplet” https://www.digitalocean.com/docs/droplets/how-to/add-ssh-keys/to-existing-droplet/

So they are saying to use ssh-copy-id. But how can I use this if I can’t login via SSH? I get the same - Permission denied (publickey).

Then I tried to login with “access console” from DO control panel. When it opens I can’t type anything there. I googled it and found out that quite a few people can’t type there. Some fixed it with pressing Ctrl+C, Ctrl+D or some other command. Yet nothing of that sort helped me. I tried it with two Browsers (Chromium and Firefox).

So I don’t know what else to do here. I can’t just create a new droplet, because I have important files in this one.

So what am I missing here about SSH? Can I login to server from my local machine without SSH, with some password? Also DO seems good at creating tutorials, so why don’t they create one about this? Because it seems that a quite lot of people are struggling with this.

I can provide more information if needed. Thanks in advance.