The bash file has dos line endings. To fix the issue, follow the this answer.

How do we know? @KamilCuk commented a good explanation.

The line : not found test.sh: starts with a :. It looks like: shell: test.sh: \r: not found, but the : not found part was moved to the beginning of the line. And also -version does not work, which would not if it would be -version$'\r'