Cups is required to be installed in the host system

sudo apt-get install python3 python-dev python3-dev
build-essential libssl-dev libffi-dev
libxml2-dev libxslt1-dev zlib1g-dev
python-pip libcups2-dev

overall please install libcups2-dev or its replacement you wont be able to install pycups without it

server based on https://gist.github.com/mdonkers/63e115cc0c79b4f6b8b3a6b797e485c7