you can use this ${properties.jcr:created.getTime.toString}output will be - Fri Mar 11 14:54:36 IST 2022

You have to write custom js for that.Please find the referencehttp://experience-aem.blogspot.com/2021/01/aem-cloud-service-validate-asset-file-extensions-upload.html

There is lots of blog and video . https://experienceleague.adobe.com/docs/experience-manager-htl/using/getting-started/getting-started.html?lang=enhttps://aem4beginner.blogspot.com/htl-sightly-code-snippetshttp://www.sgaemsolutions.com/2018/03/deep-dive-in-htlsightly-in-aem-63.html

you have to mock the service and after that you have to register the service ex:-@MockMyAccountService myAccountService;@BeforeEachpublic void setUp() throws Exception {ctx.registerService(MyAccountService.class, myAccountService);ctx.addModelsForClasses(test.class);testModel=ctx.request().adaptTo(test.class);follow this document.https://wcm.io/testing/aem-mock/usage.html