About HTML customize with Estimate and Credit Note

Hi there, I am new here and I want to ask you guys something. I have been able to make a Custom Template for my Invoice with my own HTML formatting etc., but when I turn to the Estimate and the Credit Note; sounds like I don't have that option of custom HTML. Am I right about this, or is this function hidden somewhere I don't know ? I think that if the invoice have this feature than other documents should have it too, because most of us need the documents in the same style and format; like branding identity.

Thank you for your time reading the message.

Kind regards,