While building project that contains WebSocket from Photon and WebSocket from Moralis i had some troubles with building the project.
You could join Discord and ask in a channel specific to unity help
Which version of Unity and the Moralis SDK are you using? Is this from a Moralis tutorial project or your own?
These threads may help:
Ethereum Unity3D Boilerplate Questions - Moralis Web3 Forum - Largest Web3 Dev Community 