use ECDSA & ERC2771 from @openzeppelin

contracts/p2pix.sol

@@ -9,6 +9,7 @@ pragma solidity ^0.8.19;
 ///
 
 import { OwnerSettings, ERC20, SafeTransferLib } from "contracts/core/OwnerSettings.sol";
+import { ERC2771Context as ERC2771 } from "@openzeppelin/contracts/metatx/ERC2771Context.sol";
 import { BaseUtils } from "contracts/core/BaseUtils.sol";
 import { DataTypes as DT } from "contracts/core/DataTypes.sol";
 
@@ -34,14 +35,16 @@ contract P2PIX is BaseUtils {
         address _reputation,
         ERC20[] memory tokens,
         bool[] memory tokenStates
+        address trustedForwarder,
     ) 
+        ERC2771(trustedForwarder)
         OwnerSettings(
             defaultBlocks, 
             validSigners, 
             _reputation, 
             tokens, 
             tokenStates
-        ) 
+        )
         payable {/*  */}
 
     /// @notice Creates a deposit order based on a seller's