How can I create a branch from an Argo workflow?

I am trying to send a HTTP post request in Argo workflows to create a branch in GitHub. It keeps failing and I am not able to figure out why. It looks like something sticky and small, and I would appreciate any help in figuring this out.

While executing, I just see a message successCondition 'response.statusCode == 201' evaluated false. I don't see anything in logs.

Here is my workflow:

apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
  generateName: http-template-
spec:
  entrypoint: main
  serviceAccountName: argo-workflow-sa
  templates:
    - name: main
      steps:
        
        - - name: getmainsha
            template: get-sha
            arguments:
              parameters:
                - name: url
                  value: "https://api.github.com/repos/<owner>/<repo>/git/refs/heads/main"

        - - name: print-main-sha
            template: print
            arguments:
              parameters:
                - name: message
                  value: "{{=jsonpath(steps.getmainsha.outputs.result, '$.object.sha')}}"

        - - name: generate-branch-name
            template: generate-unique-name
            arguments:
              parameters:
                - name: string-name
                  value: "new-branch"

        - - name: create-branch-github
            template: create-branch-post
            arguments:
              parameters:
                - name: url
                  value: "https://api.github.com/repos/<owner>/<repo>/git/refs"
                - name: branch-name
                  value: "{{steps.generate-branch-name.outputs.result}}"
                - name: main-branch-sha
                  value: "{{=jsonpath(steps.getmainsha.outputs.result, '$.object.sha')}}"
        
    
  #--------------------------------------------------------------templates-----------------------------------------------------------------------------#  

    - name: print
      inputs:
        parameters:
          - name: message
      container:
        image: docker/whalesay:latest
        command: [cowsay]
        args: ["{{inputs.parameters.message}}"]

    - name: get-sha
      inputs:
        parameters:
          - name: url
      http:
        timeoutSeconds: 20 # Default 30
        url: "{{inputs.parameters.url}}"
        method: "GET"
        headers:
          - name: "Accept"
            value: "application/vnd.github+json"
          - name: "Authorization"
            value: "Bearer <Token>"
          - name: "X-GitHub-Api-Version"
            value: "2022-11-28"
        successCondition: "response.statusCode == 200"

    - name: generate-unique-name
      inputs:
        parameters:
          - name: string-name
      script:
        image: python:alpine3.6
        command: [python]
        source: |
          import random
          i = random.randint(1, 1000)
          print('refs/heads/'+'{{inputs.parameters.string-name}}'+'-'+str(i))          

    - name: create-branch-post
      inputs:
        parameters:
          - name: url
          - name: branch-name
          - name: main-branch-sha
      http:
        timeoutSeconds: 20 # Default 30
        url: "{{inputs.parameters.url}}"
        method: "POST"
        headers:
          - name: "Accept"
            value: "application/vnd.github+json"
          - name: "Authorization"
            value: "Bearer <Token>"
          - name: "X-GitHub-Api-Version"
            value: "2022-11-28"
        body: "{'ref':{{inputs.parameters.branch-name}},'sha':{{inputs.parameters.main-branch-sha}}}"
        successCondition: "response.statusCode == 201"

I expect a branch to be created in GitHub.

So silly of me to make this mistake.

As per the official github documentation the ref in the request body should be like this "ref":"refs/heads/<branch-name>".

Github api create reference

Here is the updated template

kind: Workflow
metadata:
generateName: expand-pvc-template-
spec:
entrypoint: main
serviceAccountName: argo-workflow-sa
arguments:
parameters:
- name: uri
value: "<github-uri>"
templates:
- name: main
steps:
- - name: create-branch-github
template: github-http-post-put
arguments:
parameters:
- name: url
value: "{{workflow.parameters.uri}}/git/refs"
- name: method
value: "POST"
- name: requestbody
value: |
{
"ref":"refs/heads/new-branch",
"sha":"<main-branch-sha>"
}
- name: success-condition
value: "response.statusCode == 201"
--------------------------------------------------------
- name: github-http-post
inputs:
parameters:
- name: url
- name: method
- name: requestbody
- name: success-condition
http:
timeoutSeconds: 30
url: "{{inputs.parameters.url}}"
method: "{{inputs.parameters.method}}"
headers:
- name: "Accept"
value: "application/vnd.github+json"
- name: "Authorization"
value: "Bearer <>"
- name: "X-GitHub-Api-Version"
value: "2022-11-28"
body: "{{inputs.parameters.requestbody}}"
successCondition: "{{inputs.parameters.success-condition}}"