AM 6.0 OAuth 2.0 public "pkce" client requesting access token with cURL

am_oauth2_pkce_access_token.bash

authz_code=$(curl -s -w "%{redirect_url}" 'http://am-service.sample.svc.cluster.local/openam/oauth2/authorize?response_type=code&client_id=pkce&redirect_uri=http://localhost:9999&scope=openid&code_challenge=code_verifier' \
-H 'Cookie: iPlanetDirectoryPro='$(curl -s 'http://am-service.sample.svc.cluster.local/openam/json/realms/root/authenticate' \
    -X POST \
    -H 'X-OpenAM-Username:amadmin' \
    -H 'X-OpenAM-Password:password' \
    | sed -e 's/^.*"tokenId":"\([^"]*\)".*$/\1/') \
| sed 's/^.*?code=\([^&]*\).*$/\1/') \
&& curl 'http://am-service.sample.svc.cluster.local:80/openam/oauth2/access_token' \
-X POST \
--data 'client_id=pkce&redirect_uri=http://localhost:9999&grant_type=authorization_code&code='$authz_code \
-H 'Content-Type: application/x-www-form-urlencoded'