git diff command to show difference between default main branch and PR we raised , file name of those files with full path

it fetch origin $BASE_BRANCH
  git diff --name-only origin/$BASE_BRANCH...HEAD
  shell: bash --noprofile --norc -e -o pipefail {0}
  env:
    pythonLocation: /__w/_tool/Python/3.12.4/x64
    LD_LIBRARY_PATH: /__w/_tool/Python/3.12.4/x64/lib
fatal: ambiguous argument 'origin/...HEAD': unknown revision or path not in the working tree.
Use '--' to separate paths from revisions, like this:
'git <command> [<revision>...] -- [<file>...]'
Error: Process completed with exit code 128.