a problem could be that you seem to have pip installed both anvil and anvil-uplink
these may have conflicts since the pypi package named anvil is not associated with anvil.works.
Things to try:
pip uninstall anvil
pip3 install anvil-uplink
# sometimes pip3 may be required depending on how python is running locally
also check out this thread
in your script
import anvil
print(anvil.__file__)
# you may not be importing the anvil-uplink pypi package but something else
# go to this file and see what it is - change the name of the file, rinse and repeat
print(dir(anvil))
# BlobMedia, Button, ...
# if you don't get the obvious anvil dir then you are importing the wrong anvil
You can also try running the uplink script in a virtual environment.
The advantage here is that you install packages within the virtual environment rather than globally.