Hi Guys, How can I remove the custom button added via workflow on vendor form using SuiteScript?

Wouldn't it make more sense to update the workflow so that it doesn't show the button conditionally in the first place? To try and answer the question you asked, I believe you'd need to use the record.removeButton({ id: 'custpage_{yourbuttonid}' }); . However, I don't know what the id of a button created via workflow would be sourced.