I'm trying to use OpenSeaJS to buy an NFT from the Rinkeby OpenSea Marketplace.

I managed to buy NFTs using openseajs, what I would like to do now is to set a custom gas price.

Here is what I tried, I override the default value of the gasPriceAddition property of the OpenSeaPort class, to set it to 1ETH (1000000000 gwei).

The transaction is successful and I purchased the NFT but when I check the corresponding transaction on etherscan.io, I don't find the gas price value I set.

const seaport = new OpenSeaPort(
  provider,
  {
    networkName: NETWORK === "mainnet" ? Network.Main : Network.Rinkeby,
  },
  (arg) => console.log(arg)
);

seaport.gasPriceAddition = new BigNumber("1000000000");