How to pass an Interface object in a constructor parameter?

I don't know how to deploy this contract whit HARDHAT because there is an Interface object in the constructor.

Please can someone explain to me how to initialize IUniswapV2Pair _pair

IUniswapV2Pair is a Uniswap Library written in Solidity.

  const Unitest = await hre.ethers.getContractFactory("Unitest");
  const unitest = await Unitest.deploy(int256 .....,
        uint256 .... , IUniswapV2Pair(?????));

  await unitest.deployed();

  console.log("unitest deployed to:", unitest.address);