With cryptocurrencies, transactions are added to the network by miners or validators. In exchange for adding the transactions users have to pay a fee. Minke is a gasless wallet on Polygon. You won't need the native token or need to pay transaction fees.

If you imported your wallet via another wallet (not via seed phrase) you will still need MATIC on the Polygon network.

On Ethereum you need ETH. You can buy ETH in-app through Apple Pay, Google Pay and local bank transfer methods.