How to customize form placeholder text from CMS?

Hi - I’m building a marketplace and trying to create an editable ‘my profile/dashboard’ section in which they can update profile info (email, name etc etc).

Is there any way in which i can use the form feature to do this, pulling in the existing info in the CMS into the form placeholder so they can see what this information already is in the field? They could then edit it and re-submit the form to change their info.

I’ve trawled the forms and it suggests using some form of embed, however no matter what I do this doesn’t work and it’s not clear how this can be assigned to each specific form field? Thanks!