I am looking to build functionality where I can completely build an email body as well as the list of recipients within apex then make a callout to Marketing cloud passing it all the data to then send the email. I am having issues finding documentation to help as I am trying to do this. Currently I am able to callout and authenticate into Marketing cloud and get a refresh token but I can't find documentation on what functions to do the next steps (sending an email). I found messageDefinitionSends but this seems to be to send something from a journey item which is not what I'm looking to do. I am basically looking to send an email using a salesforce report for the recipients as you can do in the UI of Marketing cloud but through the API.
Any help or suggestions are appreciated!