Unable to implement internal offer letter

Summary:

Content (please ensure you mask any confidential information):

We want to create a new offer letter template for internal employees, such that we an internal employee applies for a new position and gets hired we can offer them a new offer letter.

We already have a data model for offer letter for candidates, but we aren't able to incorporate employee details as well in it.

Has anyone already have a offer letter created for internal employee ? If so , have you linked it to the candidate offer letter data model ?

Version (include the version you are using, if applicable):

23c