I was going crazy with this (I’m very novice), I hope this helps someone. Basically, if you want to set the “Rich Text Block” from another blueprint, you will notice that, place the blueprint where it is (in my case “Dialogue Widget”) and take from it the variable of your “Rich Text Block” (remember to activate it as a variable when creating it) (in my case “NEW Spoken Text”); you will see that you cannot use the “SetText (text)” node as you normally do with text. It is because the “Target” is “text” and not “Rich Text”.
To make it work you have to get from your own “Rich Text Block” node the node by typing “Set Text Widget”; only then the correct “Set Text” appears.
Do it every time you need it because copying and pasting it has given me some problems.
How to extract the gift text, in case it helps someone else