#aws ssm put-parameter --name "test123" --type "String" --value "MyValue"
#{
#  "Version": 1,
#  "Tier": "Standard"
#}

Note:- If the Value contains a URL, it will create an error:-

$ aws ssm put-parameter --name "/repo/testpar3" --value "https://server/repo3.git" --description "repo_backup" --type "String"

Error parsing parameter '--value': Unable to retrieve https://server/repo3.git: Could not connect to the endpoint URL: "https://server/repo3.git"

Fix is to use:-

$ aws configure set cli_follow_urlparam false

$ aws ssm put-parameter --name "/repo/testpar3" --value "https://server/repo3.git" --description "repo_backup" --type "String"
{
    "Version": 1,
    "Tier": "Standard"
}

$ aws ssm get-parameters --names "/ami/AMZN2/latest" --query "Parameters[*].{Value:Value}" --profile nonprod
[
    {
        "Value": "ami-05432161ea123456"
    }
]
$

This uses an option to pattern match:-

$ cat parameters.sh
#!/bin/bash
# Get the Name output from command, this requires 
# export AWS_DEFAULT_OUTPUT="json", text as an output clearly won't work with ''jq''

export AWS_DEFAULT_OUTPUT="json"
aws ssm describe-parameters --parameter-filters "Key=Name, Values=/repo/testpar, Option=Contains" | jq '.[] | .[].Name'


$ ./parameters.sh
"/repo/testpar1"
"/repo/testpar2"
"/repo/testpar3"
$

session = boto3.session.Session()
ssmsession = session.client('ssm')
 
parameter_subnets = '/config/SubnetIds'
 
def readparameter(parameter):
    parameter_response = ssmsession.get_parameter(Name=parameter)
    value = parameter_response['Parameter']['Value']
 
    return parameter_response, value
 
raw_subnet_info, sub_value = readparameter(parameter_subnets)

    ssm_client= boto3.client("ssm")
    ssmresponse = ssm_client.put_parameter(
        Name='boto3_lambda_layer_test',
        Description='ARN for boto3 lambda layer',
        Value=response['LayerArn'],
        Type='String',
        Tier='Standard',
        DataType='text' )

import boto3
 
 
def readparameter(parameter):
    parameter_client = boto3.client('ssm')
    parameter_response = parameter_client.get_parameter(
        Name=parameter,
        )
    return parameter_response
 
 
 
def lambda_handler(event, context):
 
    parameter_source_bucket = '/FULL/PATH/SourceBucket'
 
    source_bucket = readparameter(parameter_source_bucket)
    # {'Parameter': {'Name': '/FULL/PATH/SourceBucket', 'Type': 'String', 'Value': 'repo-development', 'Version': 1, 'LastModifiedDate': datetime.datetime(2022, 8, 4, 10, 54, 46, 480000, tzinfo=tzlocal()), 'ARN': 'arn:aws:ssm:eu-west-1:97112341234123:parameter/FULL/PATH/SourceBucket', 'DataType': 'text'}, 'ResponseMetadata': {'RequestId': '351fdcf9-37cd-41b6-aed7-6de291dddedb', 'HTTPStatusCode': 200, 'HTTPHeaders': {'server': 'Server', 'date': 'Thu, 04 Aug 2022 11:38:52 GMT', 'content-type': 'application/x-amz-json-1.1', 'content-length': '265', 'connection': 'keep-alive', 'x-amzn-requestid': '351fdcf9-37cd-41b6-aed7-6de291dddedb'}, 'RetryAttempts': 0}}
 
    print(source_bucket['Parameter']['Value'])
 
    }

Reference the value in ParameterStore in the Parameters section of the CF Template.

Then this value isa available to the CF Template with !Ref.

AWSTemplateFormatVersion: '2010-09-09'
Description: CF for Automation Project
Parameters: 
  AccountNumber1:
    Type: AWS::SSM::Parameter::Value<String>
    Default: AccountNumber1
    Description: AccountNumber1
 

Resources:
  Policy:
    Type: 'AWS::IAM::ManagedPolicy'
    Properties:
      Description: 'Policy for Automation Project'
      PolicyDocument:
        Version: '2012-10-17'
        Statement:
          - Effect: Allow
            Action:
            - logs:CreateLogStream
            - logs:PutLogEvents
            Resource:
              - !Join
                  - ':'
                  - - 'arn:aws:logs:*'
                    - !Ref AccountNumber1
                    - 'log-group:/aws/lambda/*:*'
     
    Roles:
        - !Ref MyReportRole