Getting the Agreement ID and placing signature fields in specific locations on the document

I am using power automate to automate some of our processes around sending agreements out. Basically when another process drops the document into a specific SharePoint doc library, it triggers my power automate flow to pick up the doc and send off for signing. That all works well, but the issue is I need to place the signature fields on the document in specific locations. From my research it appears I need to pull the agreementID (Not the DocumentID) while the agreement is in authoring mode so that I can add the form fields. I can't figure out how to get the agreementID back via the API (there doesn't seem to be a pre-built power automate connector for that). And also assuming my logic is correct about the placing of the signature fields on the form. 

Any help would be greatly appreciated!