Add the following content to your WORKSPACE:
load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
git_repository(
name = "rules_python_pdm",
remote = "https://github.com/xulongwu4/rules_python_pdm.git",
tag = "v1.1",
)
load("@rules_python_pdm//:environment.bzl", "pdm_environment")
pdm_environment(
name = "pdm_environment",
)
register_toolchains("@pdm_environment//:pdm_toolchain")