In Magento 2 How to Override phtml or layout core files?
By : scottjnoe
Date : March 29 2020, 07:55 AM
Hope that helps i solved this problem. if you want to override any core files, you simply use reference name and this reference name passed to referenceBlock name="passit". For conatct us file override, first you get the original file of contactus form.phtml and after that find it's layout file contact_index_index.xml and get the reference name like "contactForm".