# 1. set the founder accountsource_account=Stellar.TxBuild.Account.new("GDC3W2X5KUTZRTQIKXM5D2I5WG5JYSEJQWEELVPQ5YMWZR6CA2JJ35RW")# 2. set the next sequence number for the founder account{:ok,seq_num}=Stellar.Horizon.Accounts.fetch_next_sequence_number(Stellar.Horizon.Server.testnet(),"GDC3W2X5KUTZRTQIKXM5D2I5WG5JYSEJQWEELVPQ5YMWZR6CA2JJ35RW")sequence_number=Stellar.TxBuild.SequenceNumber.new(seq_num)# 3. build the create_account operationoperation=Stellar.TxBuild.CreateAccount.new(destination:"GDWD36NCYNN4UFX63F2235QGA2XVGTXG7NQW6MN754SHTQM4XSLTXLYK",starting_balance:2)# 4. build the tx signaturessigner_key_pair=Stellar.KeyPair.from_secret_seed("SECRET_SEED")signature=Stellar.TxBuild.Signature.new(signer_key_pair)# 5. submit the transaction to Horizon{:ok,base64_envelope}=source_account|>Stellar.TxBuild.new(sequence_number:sequence_number)|>Stellar.TxBuild.add_operation(operation)|>Stellar.TxBuild.sign(signature)|>Stellar.TxBuild.envelope(){:ok,submitted_tx}=Stellar.Horizon.Transactions.create(Stellar.Horizon.Server.testnet(),base64_envelope)