I have two stages which are in same Jenkins files,The requirement is i want to stash a repository on stage('AAA') and unstash from the another kubernetes pod within stage('BBB')

I have come across a code like below, after struggling many hours, I could-not fix it.

        stage('AAA') {
            steps {
                script {
                // HERE WE CLONES MANY GIT REPOSITORIES into app directory
                //Please repository is cloned to the {PWD}/app directory
                }
                dir('app') {
                stash name: "sunnyday"
                }
            }
        }
        stage('BBB') {
            agent {
                kubernetes {
                    label "dotnet"
                    yaml """
            apiVersion: v1
            kind: Pod
            metadata:
              namespace: sandbox-test
            spec:
              containers:
              - name: dotnet-core-sdk
                image: mcr.microsoft.com/dotnet/core/sdk:2.2
                imagePullPolicy: IfNotPresent
                command:
                - /bin/cat
                tty: true
            """        
                }
            }
            steps {
                container(name: "dotnet-core-sdk") {
                    unstash sunnyday
                }
            }
        }