Sepolia is Ethereum testnet.

You can switch blockchain to Sepolia to test Collectify functions before deploy on the mainnet for free.

Below are some useful links for Sepolia network:

Faucet (Get free token):

https://www.alchemy.com/faucets/ethereum-sepolia

https://faucet.paradigm.xyz/

Etherscan https://sepolia.etherscan.io/

Uniswap (Swap for ERC20 tokens) https://app.uniswap.org/#/swap?chain=sepolia

Opensea testnet https://testnets.opensea.io/

NFT Validator https://erc721validator.org/