The installation guide for Hologram Shaders Pro is relatively straightforward. If you got the pack from the Unity Asset Store, you can use the package manager to install the pack, and if you got it from itch.io or Gumroad, then you will receive a .unitypackage file - use Assets -> Import Package -> Custom Package to install it.
Once the pack has been installed, each effect will be available to you in the Shaders folder, and there is a Demo scene with all the effects on display. All shaders should be configured to work with all three pipelines from the start, and no further configuration is needed.