@CaiAnqi-9995 Thanks for reaching out.
You need to leverage the Export email (V2) action and pass the message ID from your trigger and then leverage the SharePoint action as per your need. In my case I have used the Create File action and passed the Body of my Export email (V2) action in the File content of Create file action.
In case if you are only looking for the text content and not the full email then please let me know. As the above will save all the attachments screenshot etc. in your email and save it as the eml file or any extension as per you have defined.