To use this you will have a form and with this form and place, a code embed inside. Within this, you have to use code and I know, this is code but unfortunately it is useful from time to time. 

Put it in like this:

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Then place this code in there. The names have to match up with the field in Memberstack data as well.

The code: 

<input type="hidden"data-name="Webflow Sender ID" ms-data="webflow-id" >

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