Pipeline stack which uses cross-environment actions must have an explicitly set region - aws-cdk

Question

I am trying to create an AWS Code Pipeline to create a DynamoDB table in one of the stages. I was able to successfully deploy the same code with CDK v1. now trying to replicate the same on CDK v2. I am getting an error Pipeline stack which uses cross-environment actions must have an explicitly set region
Here's the complete code:
import { Stack, StackProps, Stage, StageProps } from "aws-cdk-lib";
import { AttributeType, Table } from "aws-cdk-lib/aws-dynamodb";
import {
CodePipeline,
CodePipelineSource,
ShellStep,
} from "aws-cdk-lib/pipelines";
import { Construct } from "constructs";
export class DdbStack extends Stack {
constructor(scope: Construct, id: string, props?: StackProps) {
super(scope, id, props);
new Table(this, "TestTable", {
partitionKey: { name: "id", type: AttributeType.STRING },
});
}
}
class MyApplication extends Stage {
constructor(scope: Construct, id: string, props?: StageProps) {
super(scope, id, props);
new DdbStack(this, `${id}-ddb`, {});
}
}
export class PipelineStack extends Stack {
constructor(scope: Construct, id: string, props?: StackProps) {
super(scope, id, props);
const pipeline = new CodePipeline(this, `${id}-PipelineStack-`, {
crossAccountKeys: true,
selfMutation: false,
pipelineName: "MangokulfiCDK",
synth: new ShellStep("Synth", {
input: CodePipelineSource.connection("gowtham91m/mango-cdk", "main", {
connectionArn:
"arn:aws:codestar-connections:us-west-2:147866640792:connection/4b18bea2-9eb6-47b1-bbdc-adb3bf6fd2a9",
}),
commands: ["npm ci", "npm run build", "npx cdk synth"],
}),
});
pipeline.addStage(
new MyApplication(this, `Staging`, {
env: {
account: "123456789123",
region: "us-west-2",
},
})
);
pipeline.buildPipeline();
}
}