Why dd() function is not show anymore in preview? Some versions ago i could write dd in controller after that in Postman i requested and saw html dd answer
Welcome to the Postman Community! 
What’s the response in the main view?
Have you tried selecting a different format and then viewing the preview?
What did it show in the preview section previously?
So, do you wanna say i need every time change the mode from json to html? What for did you do that? Couple version ago it was easily, i wrote dd function in code and postman could figured it out for himself how to parse, html or json
Your dd function is very contextual to you so I have no idea what that is doing without you providing an example of the response body and what that was previewing?
Are you able to share an example of that?
I want to bring in @docking-module-admin to the conversation to talk more about the newly updated response experience - He is the best person to give you all the correct information here. 
Hey @descent-module-engi2 we made this update to give users who use JSON a preview that can better preview their data. One change we made was to have to preserve the last language selection you made for a tab. So you only have to make the change once and then the language will persist.
If you are looking to have something with more control using the visualizer for your response might better serve your needs: Visualize request responses using Postman Visualizer | Postman Docs.