Unable to install hplip

I have just downloaded hplip-3.20.11.run and am running Ubuntu 18.04

When I run sh hplip-3.20.11.run it creates the sub-directory and extracts the archive but the ends with:

hplip-3.20.11.run: 1: eval: ./hplip-install: Permission denied

If I cd into the directory and run:

$ sh hplip-install

I get the error:

hplip-install: 26: hplip-install: ./install.py: Permission denied

If I change the line in the script to sh ./install.py -i $* and run the install script again I get:

$ sh hplip-install
from: can't read /var/mail/__future__
./install.py: 23: ./install.py: __version__: not found
./install.py: 24: ./install.py: __title__: not found
./install.py: 25: ./install.py: __mod__: not found
./install.py: 26: ./install.py: __doc__: not found
import-im6.q16: not authorized `getopt' @ error/constitute.c/WriteImage/1037.
import-im6.q16: not authorized `os' @ error/constitute.c/WriteImage/1037.
import-im6.q16: not authorized `sys' @ error/constitute.c/WriteImage/1037.
import-im6.q16: not authorized `time' @ error/constitute.c/WriteImage/1037.
import-im6.q16: not authorized `re' @ error/constitute.c/WriteImage/1037.
from: can't read /var/mail/base.g
from: can't read /var/mail/base
./install.py: 42: ./install.py: Syntax error: "(" unexpected

What am I doing wrong???

Thanks