# pick ONE canonical dir (I'll use /home/bbl/html/w1hd-tracker)
cd /home/bbl/html/w1hd-tracker

# create venv if missing; harmless if it already exists
python3 -m venv venv

# activate and install aprslib
source venv/bin/activate
pip install --upgrade pip aprslib

# run your script with the venv python
python sendBILL.py