You may want to always have the same recipient, approver, or signer in the document workflow every time you use the template.
To add the specific person, simply fill in their email in the search field and add them to the template, see the image below.
Please note: If you want to add a specific person as an approver. Then you need to add either another specific signer or add a role (set the role to signer) if you don't know who the signer will be.
You can always add the approver to the template as a role and fill in their information when creating a new send-out.
You can also add permanent recipients to a template if you, for example, always want a certain email to get the document when that template is used. Then you add them as an only view if they are not to sign the document.