Recover FTM sent to ERC20 address
FTM moved to their own mainnet in December 2019, but they still share the same address format as any other ERC20 token.
This means that you can successfully generate a FTM address in any Ethereum or ERC20 wallet, but you will not be able to view or spend the FTM tokens.
The only way to access your FTM balance is by using an FTM mainnet compatible wallet.
To access funds incorrectly sent to an ERC20 address, you can open that address inside the FTM Wallet by using the private key for your ERC20 FTM address.
Get the private key for the specific address you sent the funds to.
Second, follow FTM's guide on recovering your balance from that private key:
⚠️ 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.