How to Create 3D Type in Illustrator: https://youtu.be/0jnojoBWOdo
This video goes over one method for creating 3D extruded text inside Adobe Photoshop. The effect is primarily achieved by stacking drop shadows on top of each other in a layered method until eventually you get a solid 3D effect.
As most things Photoshop there are no doubt many potential ways to create similar effects, so if you know of any others, feel free to share them (or any questions you have) in the comments section!
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