ruby openssl CSR request failing with error: The submission failed: Error Parsing Request ASN1 bad tag value met(ASN: 267 CRYPT_E_ASN1_BADTAG)

I am trying to submit a CSR request in the following way:

require 'openssl'
require 'json'

  def public_key_info
    key_info = private_key.public_key.to_pem
    key_info = key_info.sub! '-----BEGIN PUBLIC KEY-----', '-----BEGIN CERTIFICATE REQUEST-----'
    key_info = key_info.sub! '-----END PUBLIC KEY-----', '-----END CERTIFICATE REQUEST-----'
    key_info
  end


  # "Creating a new 2048bit RSA Keypair..."
  def private_key
    @private_key = OpenSSL::PKey::RSA.new 2048
  end
   payload = { 
    "CsrData" => public_key_info,
    "certTemplate" => "MyTemplate"
  }

 encoded = JSON.generate(payload)

p "Payload is #{encoded}"

 response = RestClient::Resource.new(
   'http://myURL/GenerateCertificateUsingCsr',
 ).post encoded, :content_type => 'application/json', :accept => 'text/plain'

  response_json = JSON.parse(response.body)
  p response_json

This is the error I get:

{
    "certTemplate":"MyTemplate",
    "CsrData":"-----BEGIN CERTIFICATE REQUEST-----\nMIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAuWeK196VcjZZFbKyEjpj\n8I6DjHbwiMi9I10tV41OEt9Ozp+M0V6TYOKNlJTXGxNUHD0lXFJBlS2z/PLQbW/3\n6C9xRkIclve5Uq8J2NmubnR9+NOt/cjPb4EJtMlxySq5cWOqEyq4UirUEfch9HMC\nkLwJ0MPdrDatZqfIv1IvhBiKfyqWV2jds3X60NlmvyGxnrd54dO8/OqNJNmw2BP9\n3aa21asRqB7oPW2H49o2gwDxF6ZEwymAFvU4jvO+BQLRDYTm8GslHyX9kCXWnYHg\nX7gqvek/mu7KqyIB44YyOjGYkVX76El32B08ruKlc+xZ8kFWC1bMzwZNoFEBKO6D\n9QIDAQAB\n-----END CERTIFICATE REQUEST-----"


}


  {"ErrorCode"=>1005, "ErrorMessage"=>"The submission failed: Error Parsing Request  ASN1 bad tag value met. 0x8009310b (ASN: 267 CRYPT_E_ASN1_BADTAG)", "Return"=>false, "p12Data"=>nil, "certexpdate"=>nil, "serialNo"=>nil}
=> true

But if I create the CSR request from the command line:

openssl req -out mytest.csr -new -newkey rsa:2048 -nodes -keyout mytest.key

Then converted the CSR so replace new line with \n string.

Then prepare a Json payload:

{
    "certTemplate":"MyTemplate",
    "CsrData":"-----BEGIN CERTIFICATE REQUEST-----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\nKAF82Vl9kvwOwyD8sPN19V9ldmZpMhQ/2hsuHxRLAnlwHYhqfl/9\n-----END CERTIFICATE REQUEST-----"
}

the above CSR request works fine.

What am I doing wrong with the ruby code above?