How to send an MTOM request by SOAP UI?

I have tried to send an MTOM request, and I followed some instructions.

So, I have set 'Enable MTOM' as true, which is descirbed at https://www.soapui.org/docs/soap-and-wsdl/attachments.html

But I have failed, and the HTTP headers are as follows:

Tue Jan 28 10:21:08 KST 2020: DEBUG: >> "Accept-Encoding: gzip,deflate[\r][\n]"
Tue Jan 28 10:21:08 KST 2020: DEBUG: >> "Content-Type: text/xml;charset=UTF-8[\r][\n]"
Tue Jan 28 10:21:08 KST 2020: DEBUG: >> "SOAPAction: ""[\r][\n]"
Tue Jan 28 10:21:08 KST 2020: DEBUG: >> "Content-Length: 1327[\r][\n]"

On another web-page, https://community.smartbear.com/t5/SoapUI-Open-Source/SOAPUI-response-with-attachment/td-p/186677 , the request header contains:

Content-Type: application/xop+xml; charset=UTF-8; type="text/xml"

Anyway, my goal is:

- I want to send a right MTOM request and get an MTOM response via SOAP UI.

- For the above, I want to set the http headers like this(The soap provider told us to set the Acceept):

Content-Type: multipart/related; type="application/xop+xml";
SOAPAction: ""
MIME-Version: 1.0
Accept: multipart/related; type="application/xop+xml"

What should I do?