How to fix unmet dependencies error
Spotipo depends on a number of packages, those will be installed automatically if the corresponding repositories are enabled.
If not you might see an error like below
The following packages have unmet dependencies:
spotipo : Depends: python-pip but it is not installable
Depends: supervisor but it is not installable
Depends: redis-server but it is not installable
E: Unable to correct problems, you have held broken packages.
How to add all the required repositories?
There is an awesome tool https://repogen.simplylinux.ch/ which generates the sources for all standard ubuntu distributions.
First backup your existing sources.list just in case
sudo cp /etc/apt/sources.list /etc/apt/sources.list.bkp
Go to the above website and select Universe and Multiverse repositories
Now scroll all the way down and press the generate button
It will generate a set of commands for you to run
Now add spotipo repository again and proceed with installation
echo "deb http://repo.spotipo.com/ ubuntu main" | sudo tee --append /etc/apt/sources.list
sudo apt update
sudo apt install spotipo