Hello @jsmith, welcome to the forum and for reaching out!
I am taking a guess here that “the DCP profile photo” simply means a photo you took of a color chart, correct? You then want to use that calibration and apply it to other photos?
There is no copy-and-paste way to do that in RawTherapee I am afraid. It will require the use of (rather finnicky) tools outside of RawTherapee, called DCamProf and Argyll, or commercial software.
There is a description here if you want to try it out yourself: How to create DCP color profiles - RawPedia