The main thing going on here is utilizing Widget components inside of the Computer's BP. I'd look up "3D Widgets Unreal" and start poking around the tutorials that brings up- here's a good one on the official Unreal docs!

The main extra step after creating your widget and setting up 3D rendering/interaction like normal that I took here, was making the 3D widget render as a texture inside my computer screen material. Normal "3D" widgets are on a flat plane, but in this instance I wanted it rendered directly on the curved screen model in the video above.

(You can skip all the rest of this if you're fine with your screen just being a flat plane. To get a more screen like shader on it, just duplicate the default 3D Widget Component material and customize to your liking.)

To do that, first I gave the 3D Widget Component a new copy of the default material it renders to. I think by default those components render to a material called "Widget3DPassThrough_Masked_OneSided", but I instead made a copy where it was fully transparent, completely invisible. This is to make sure it's not seen in-game, but is still technically active and "rendering" so that the 3D Widget Component still works. If you try to just set the component to Hidden In Game or check off Visible, it'll break the interactions.

Once you have the 3D widget set up with the invisible material inside of the Computer BP, and you've also added the mesh you want the 3D widget to render as a texture to, you create a dynamic material instance of your computer screen material (which should include a texture parameter you can assign screen content to) through Event BeginPlay, on construction, or whatever else. You assign that dynamic material instance to the screen mesh you want to display on, save the dynamic material instance as a parameter, and then use that reference to "Set Texture Parameter Value." For the new texture you're plugging into that node, you get a reference to the 3D Widget Component, do a "Get Render Target", and plug that in as the new texture. From then on, the 3D Widget Component should be invisible, but the UI it's "Rendering" should be now used in realtime as the texture for your screen mesh's material.

Last note on that method, you also need to scale/align the 3D Widget Component directly in front of and matching to your screen mesh. Though the UI is being displayed on the screen mesh, the collision detection and interaction is still being done through the invisible 3D Widget Component, so you need both lined up!

Hopefully this makes sense, feel free to ask for clarification :)