What is the design tool for Lattice HDR-60 Video Camera Development Kit?
Lattice Diamond is listed as showing ECP3 support, but only with a paid license; normally a development kit should at least provide a node-locked / eval license for your purposes. I would try contacting Lattice as it is their kit and they should be supporting it.

Extra content: Some Lattice FPGAs have only the fact that they are currently sold and marketed by Lattice in-common, and differ significantly under the hood. For example, Lattice acquired SiliconBlue in 2011 and the iCE-family came along with them. Lattice Radiant is the new software development package for that family and has nothing to do with Diamond and the other Lattice devices.

There is also significant work being done by the open-source community in creating completely free, high-performance synthesis and implementation tools for Lattice devices (yosys). If I recall correctly, those are currently focused on iCE40 with ECP5 work in progress at the moment