Recover THETA sent to ERC20 address
Theta moved to their own mainnet in May 2020, but they still share the same address format as any other ERC20 token.
This means that you can successfully generate a THETA address in any Ethereum or ERC20 wallet, but you will not be able to view or spend the Theta tokens.
The only way to access your Theta balance is by using the official Theta Wallet.
To access funds incorrectly sent to an ERC20 address, you can open that address inside the Theta Wallet by using the private key for your ERC20 THETA address.
Get the private key for the specific address you sent the funds to.
Second, open Theta Wallet using that same private key: https://wallet.thetatoken.org/unlock/private-key
By opening your wallet in this way, the Theta Wallet will generate the same Receive address as in your original transaction, and you will see your funds there.
⚠️ WARNING ⚠️
By accessing your original wallet seed phrase or private key through the Theta web wallet, you may reduce the security of your original wallet. It might be a good idea to create a new wallet and move any funds stored in the original wallet.