iPad pro to external monitor

Your iPad Pro has a USB-C port. For connection to an external monitor, you’ll need a suitable display adapter - or USB hub that incorporates an HDMI port.

From Apple:

• USB-C Digital AV Multiport Adapter

https://store.apple.com/uk/xc/product/MUF82ZM/A

If looking for an HDMI Adapter, be aware that very few USB-C HDMI adapters/hubs support HDCP 2.0 - absence of which will inhibit the ability to output copy-protected HD media content from iPad to a connected monitor/TV over an HDMI connection.

The Apple USB-C Digital AV Multiport Adapter does support HDCP 2.0, but perhaps lacks some of the additional the flexibility afforded by some third-party USB-C hubs

You just need a dongle to connect external displays via HDMI or even VGA. However, in most cases, it will mirror your display.

are you using the Apple external dongle?

If you’re looking for a robust HDMI solution, to ensure HDCP support, I recommend that you invest in Apple’s USB-C Digital AV Multiport Adapter.

You are very welcome.