We weren't aware there was a linqpad 6. We currently have a linqpad 5 driver only. We'll see what we can do to add it.
(edit). Linqpad 6 only runs on .net core3 or .net 5. However we have a custom dialog in the driver for selecting elements using winforms. This won't work on .netcore3, only on .net 5 (but haven't tested it on .net5).
So for the time being we'll keep the linqpad5 driver and will add a linqpad 6 driver later (which will be for .net 5 only)