Ok I was actually testing wrong - this is working just fine for me. All I do is set EnableWetSign in the request body to false and I'm able to hide the SIGN ON PAPER button.
I have been testing with PHP code (which is not a type safe language) and I was mistakenly setting EnableWetSign = "False", which is the string False not the boolean value for false (0). If I set EnableWetSign to false it hides the button for me, and setting it to true enables the button, just as expected. Please check your request and make sure that you are correctly setting its value. Not sure what language you're using but maybe you're making the same mistake I was?
To disable the Sign on Paper button:
EnableWetSign = false
To enable the Sign on Paper button:
EnableWetSign = true
And here is what the request body of a REST API signature request from template call would look like
{
"accountId": "123456",
"enableWetSign": "true",
"emailSubject": "Testing Sign on Paper Button",
"emailBlurb": "This comes from PHP",
"templateId": "B977F511-CAB0.......................",
"templateRoles": [
{
"email": "test@gmail.com",
"name": "John Doe",
"roleName": "Signer1"
}
],
"status": "sent"
}