In most cases of sending the wrong address/blockchain, users will not be able to get their assets back. One of the special cases is sending ERC20 tokens to the BEP20 wallet and vice versa, users can still get that token back.
The encryption of both blockchains is similar to each other. So the same private key can generate the same wallet address in each blockchain. If you use Passphrase, different blockchains will generate different wallet addresses.
To restore ERC20 tokens you accidentally sent to the BEP20 wallet, please follow these steps:
Step 1: Copy the private key of the Binance Smart Chain wallet that you sent ERC20 tokens to.
If you forget the private key of your Binance Smart Chain wallet, follow these steps:
1.1. Click Manage -> Manage All Wallets on the home screen
1.2. Select the Binance Smart Chain wallet with which you deposited ERC20 tokens.
1.3. Select Show PrivateKey & Passphrase and copy the wallet's private key.
Step 2: Restore ERC20 wallet with the private key of BEP20 wallet
2.1. Click Manage on the home screen
2.2. Click Add Wallet.
2.2. Select the Ethereum blockchain, then select Restore Wallet.
2.3. Enter the copied Private Key and enter the wallet name.
2.4. Select Connect
After restoring your wallet, you can go to Manage -> Manage All Wallets to check.
To see the token, make sure the ERC20 wallet you just restored is activated.
If you don't see the ERC20 token on the home screen, go to Manage and select Hidden Tokens to show that token on the home screen.
To restore BEP20 tokens accidentally sent to ERC20 wallets, you just need to do the same steps.