If you’re like me, you like security a lot. And want to know what scripts are doing on your Pi.
You can run the following steps manually:

# 1) add the key for our repository
curl -L http://repository.picockpit.com/picockpit.public.key | sudo apt-key add -

# 2) add the repository
echo "deb http://repository.picockpit.com/raspbian buster main" | sudo tee --append /etc/apt/sources.list.d/picockpit.list

# 3) update package list
sudo apt-get update

# 4) install picockpit-client (press enter when asked whether you want to proceed)
sudo apt-get install picockpit-client

# 5) this will connect picockpit-client to picockpit.com. You need to provide your API key.
# the --yes parameter sets some sensible defaults. Feel free to run without it, if you want to have more control.
sudo picockpit-client connect --yes

Please note that commands need to be on one line, even if they are broken up in two lines here.

Only use one of the methods!
Please do not run both the short and elaborate instructions, choose one of the two. Otherwise picockpit-client will fail to install / start correctly.

Raspi Berry’s useful tips for Raspberry Pi beginners