python – raspberry pi zero installs old version of pymodbus

i have a raspberry Pi Zero V.1. I have pymodbus installed but struggle to get the latest version. On pypi.org the latest version is 3.11.4. The version on my pi is 3.0.0-7

If i type (after trying: pip3 install pymodbus and getting the error “This environment is externally managed….”)

sudo apt install python3-pymodbus

i get the answer: python3-pymodbus is already the newest version (3.0.0-7)

Why does the system tell me that 3.0.0-7 is the latest version if the latest version is actually 3.11.4?