Harmony Mainnet Custom RPC

Network NameHarmony Mainnet
Network URLhttps://api.harmony.one
Chain Id1666600000
Currency SymbolONE
Block Explorerhttps://explorer.harmony.one
Harmony Mainnet

If you are testing any website on Harmony Mainnet then you must have to add the RPC in your MetaMask first to start

How To Add Harmony Mainnet Custom RPC To MetaMask:

Go to Metamask and then click on the selected network and then click on the add network option