1. Go to Manage User-Defined Fields:

2. Add some User-Defined Fields:

3. Go to Screen Configuration

4. Edit a section

5. Move the field from Available Elements to Selected Elements:

6. Now the field is displayed with the other fields rather than on a separate tab:

https://www.acumatica.com/blog/technical-tuesday-universal-search-in-acumatica

Note I found gears on other tabs, that allowed you to customize the tab, hiding or bringing fields to the screen. eg Financial Tab

The screen reverted to the old view.   

It seems that GI are not available in the Modern UI only classic

Changed site back to classic

The gears disappeared. Changes made in the modern UI were not visible after it was changed back to Classic.

Interesting, I then later switched it back to Modern.  All my changes in modern UI were maintained

I hid a vat field and added a contact field

Here is a image of gears, on Financial Tab - allows company to customize view personal or company wide

I just confirmed that this works in Acumatica 2023 R1 (23.100.0138). You can see the new UI on the Sales Orders (SO301000) screen by doing the following:

First, this is what the Classic version of the Sales Orders (SO301000) screen looks like and it's what you see by default in Acumatica 2023 R1 (23.100.0138).

But you can do this secret trick in the web.config file to enable the Modern UI.

There is one more step to do though. We've made the Modern UI available, but we still need to enable it on a screen by screen basis. This is probably because Acumatica is going to phase it in a little at a time to make sure that it's working properly on each screen before making it the default for everything.

You tell a screen to use the Modern UI by going to the Site Map (SM200520) screen and setting UI to Modern like this:

Now, when I go to the Sales Orders (SO301000) screen again, I see the shiny new UI. Oooh, Ahhh, wow, amazing!

Now I can do the cool stuff that we saw demoed at Summit. For example, I can remove the VAT fields by doing this: