I'm hoping someone on this forum can lend some insight - and I will declare upfront I am new to Draytek products.

I have purchased two Draytek 920RPD to bridge a network between 2 buildings on a site that are just 10M apart and with unobstructed line of sight.

Having taken delivery - I have the two devices at home, but cannot see an easy way to setup the bridge between the two. Having trawled the Internet there is information/videos that show a configuration option of AP Bridge Point-to-Point (for example : https://www.draytek.com/support/knowledge-base/5267)

But the Point-to-Point setup as a simple option does not appear on the Web UI for the 920RPD.

Can anyone shed some light and offer guidance as to how to configure Point-to-Point bridges

Based on other wireless products, I'd guess you need to set them into WDS mode..but really I'd ask support as not many people (relatively) do PtP links so might not be any users on here...

Have a look at this video from Draytek NZ. This might help you out.
https://www.youtube.com/watch?v=EsgyN39yLI8

Unfortunately I suspect that video will not be of much use to the OP because, as he points out, the 920R does not have a "bridge point to point" option. However, as admin says, it does appear to offer a WDS facility in "General Setup". I use two AP902's to bridge in "Bridge WDS mode" and it looks to me as though enabling each 920R WDS and inputting their MAC addresses as peers of each other should work in the same way.

Set the APs up as Mesh Root & Node, connect them locally to get them to add each other's MAC address. Then increase the distance.

WDS is now part of Mesh - you can set MAC addresses manually from the WLAN General Setup page once Mesh is enabled. Potentially you could set up the WDS link manually that way, but Mesh automates that part.