Currently, OIX only supports MATIC on the Polygon network.
MATIC is the primary asset of the Polygon network, and it is also an ERC20 token on the Ethereum network.
If you have ERC20 MATIC, it is possible to bridge it to the Polygon network by using the Polygon Bridge.
However, it might be more cost effective and faster to send ERC20 MATIC to an exchange that supports MATIC on both Ethereum and Polygon, then withdraw your MATIC to your wallet on the Polygon network.
FTX and crypto.com are both options to do this (but you will need to register an account, as they are custodial exchanges).
Another option is to buy MATIC on the Polygon network: How to buy crypto
How to bridge ERC20 MATIC to Polygon MATIC using the Polygon Bridge
1. Go to Polygon Wallet. Click on Polygon Bridge.
2. To connect, click on your wallet.
3. Your wallet will ask you to sign a message to log into Polygon wallet. Click Sign.
4. To deposit ERC20 MATIC, click on the dropdown menu.
5. a) Search for MATIC in the search box, then b) click on MATIC.
6. a) Select the amount of ERC20 MATIC you want to bridge from Ethereum to Polygon, then b) click Transfer.
Note that you will need some ETH in your wallet to pay the gas fee.