Today I got up to 10.3 Transactions - Sending Ether and have deployed the Charity contract of sendingEther_answer to the Sepolia testnet, but I don't understand how the amount of Eth I send through the Donate function is set. I can click Donate where the deployed contract is displayed under "Deploy and run transactions" but this causes a donation of 0 Eth from my connected account, which I can see I've tried a few times under the list of transactions in Metamask.