I installed Ronin wallet to try this. and you can install it in Metamask. The thing is you need your private key, not your 12 word seed. To get your private key in Ronin Wallet you need to do the following:
it will ask you for the password and then will show you the private key.
Copy the private kay and then import it to the Metamask wallet. Make sure your imported wallet is in Ethereum Mainnet and your Ethereum should be there.