Remix – How to Retrieve an Already Deployed Contract with Remix

Your steps to use Remix are fine, so just two remarks that might help:

1. Make sure you have selected your contract CampaignFactory in field CONTRACT from <Deploy & Run transactions> menu. Otherwise, if you put the contract address but you haven't selected the contract, it won't deploy it in Remix. The field CONTRACT is linked to the file explorer, where you save all your contracts.

2. Your contract is apparently not compiling. Not sure what you try to achieve, your Solidity pragma and the reason to return an empty array, but you need to add the location in the return type. E.g.:

   function getDeployedCampaigns() public view returns (address[] memory) {
      return deployedCampaigns;
   }
   

3. Extra: probably not the case, but I have had issues when using Remix with https, so better to use http if your browser allows to do so.

When you send money to a smart contract, you'll have to call a payable function. It's not possible directly via Metamask, as Metamask merely sends a transaction without any data unless specifically requested to do so via its API. To send send money, you can change your Metamask to wallet B and call sendMoney() function of the contract along with some ETH.

If you want your smart contract to accept money without being called via specific function, you can define a receive function like this.

receive() external payable {
    sendMoney();
}

This tells the contract to accept payment (those sent as normal transactions as you mentioned). This is a security feature of solidity to safeguard accidental sending of ETH to smart contracts which might not have a withdrawal mechanism.