You will need the windows based AEM forms designer previously known as livecycle designer

Also do you need to merge the data captured in adaptive form with the xdp template to generate the pdf?

there is nothing specific that needs to be done. Can you please send us the form?

You will have to write custom code to assemble the pdf files and show the pdf using a custom component the custom component to display the pdf is documented 

For core component based forms the following article for creating custom submit should workhttps://experienceleague.adobe.com/docs/experience-manager-learn/cloud-service/forms/custom-submit-headless-forms/custom-submit-service.html?lang=en 

deleted the following and then restarted. IT worked for me after this. Thank GODI fix it by deleting the following:crx-quickstart/repository/segmentstore/repo.lockcrx-quickstart/launchpad/felix/cache.lockcrx-quickstart/repository/indexcrx-quickstart/launchpad/config/org/apache/sling/jcr/repoini

https://experienceleague.adobe.com/docs/experience-manager-learn/forms/some-useful-integrations/geonames-org.html?lang=en

batch is used to generate multiple pdf files from one xdp template and different data fileshttps://experienceleague.adobe.com/docs/experience-manager-learn/forms/document-services/generate-multi-record-pdf.html?lang=en 

What are they using ES4 for? Can you please provide the use cases for which ES4 is being usedthe reason I am asking is sometimes you don’t need to upgrade, you can just start using latest version of AEM forms depending on the use case 

Not possible using AFexport the data manually from the db and import it into the target db