How to create a user and copy corresponding pub file to authorized_key using AWS CloudFormation?

I am having trouble to create a user and copy the corresponding pub file called authorized_keys into the .ssh folder on the instance using AWS Cloud Formation. I do this, because I want to connect with this user using SSH. When I check the SystemLog of the created instance, it does not seem like the user is created or any file is copied as authorized_keys in the .ssh directory, this is my code:

LinuxEC2Instance:
Type: AWS::EC2::Instance
Metadata:
  AWS::CloudFormation::Init:
    config:
      users:
        ansible:
          groups:
            - "exampleuser"
          uid: 1
          homeDir: "/home/exampleuser"
      files:
        /home/exampleuser/.ssh/authorized_keys:
          content: !Sub |
            '{{ resolve:secretsmanager:
              arn:aws:secretsmanager:availability-zone:account-id:secret:keyname:
                SecretString:
                  keystring }}'
          mode: "000600"
          owner: "exampleuser"
          group: "exampleuser"

Am I missing something so that the user is created and the file is also being copied?

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Author: Benny