To create an Article $9$ security interest in the goods sold, a merchant must do what to create the security interest.

Buyer must orally agree to creating a security interest in the goods sold.

The creditor$/$lender must file a UCC$-1$ financing statement with the State.

Merchant must create a financing agreement creating the security interest in the goods sold, and buyer must sign this contract.

The creditor$/$lender must require a security interest in collateral worth more than the goods being financed by the loan.

Depreciation demands this.