TrialPad allows you to present evidence using a wired connection (with a VGA or HDMI cable) or wirelessly (using an Apple TV).
For a wired connection you'll need to use the appropriate adapter for your iPad model (whether it has a Lightning or USB-C port) to connect the iPad to the VGA or HDMI cable, which will then be connected to the projector or display monitor. (Only use genuine Apple adapters as a generic adapters from third party may not work.)
To present wirelessly the iPad will communicate with the Apple TV (4th generation or later) using Peer-to-Peer AirPlay via Bluetooth (no WiFi connection to the internet is required).
Full details, instructions, and links to the appropriate parts can be found on the attached PDF.