If you are interacting with sidechains or custom networks, we highly recommend you read our user guide here.
If you get the error "Internal JSON-RPC error" while trying to interact with other network, try the following:
- ensure the network has been added correctly. You can use Chainlist to add custom network/ tokens
- ensure you have enough native tokens from that network to pay for gas
- ensure you are using the latest version of the app or the extension
