Find the Payment Token Contract:
Interact with the Contract:
Contract tab and click on Write as Proxy or Write Contract if it is not a proxy contract.
Approve Spending:
Find the approve function in the list of available functions. You'll need to input two pieces of information:

spender address, which is the IFFixedSale contract address. This address should be provided by the project.amount of tokens you wish to allow IFFixedSale to spend on your behalf. This will be your purchase amount.<aside> 💡 The amount is in wei. Use this tool to convert the amount into wei: https://arbiscan.io/unitconverter?wei=0
e.g. If the sale is 10 WETH and you’d like to buy 3 sale tokens / nodes. The amount will be 30 ETH(1), which is 30000000000000000000 Wei(10^-18)

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After filling in the details, click "Write" to execute the transaction. Confirm the transaction in your wallet and wait for it to be confirmed on the blockchain.
whitelistedPurchaseWithCode FunctionContract -> Write Contract section.Find the whitelistedPurchaseWithCode function. Input the required parameters as follows:
paymentAmount: The amount of tokens you want to purchase.merkleProof: An empty array, this one → []_allocation: Set this to the same value as your paymentAmountcode: Input the referral code provided to you, if any.Price per Node: 0.1259 WETH
In WEI, it will be 125900000000000000

Put paymentAmount → 125900000000000000
Put merkleProof → []
Put _allocation → 125900000000000000 (same like paymentAmount)
Put code → if any, in this example, we use “if” as in “IF”
Notes:
If you want to add for more node, example for 2 Nodes it will be 125900000000000000*2 = 251800000000000000 (put it both in paymentAmount and _allocation with the same value)
After entering all the required information, click "Write" to execute the purchase. Confirm the transaction in your wallet.
<aside> 💡 Double-check all contract addresses and transaction details to avoid scams and errors
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