fn initialize(env: soroban_sdk::Env, owner: soroban_sdk::Address)
fn get_owner(env: soroban_sdk::Env) -> soroban_sdk::Address
fn allow_debit(
env: soroban_sdk::Env,
sender: soroban_sdk::Address,
receiver: soroban_sdk::Address,
token: soroban_sdk::Address,
max_amount: i128,
expiration_ledger: u32,
)
fn request_payment(
env: soroban_sdk::Env,
sender: soroban_sdk::Address,
receiver: soroban_sdk::Address,
amount: i128,
token: soroban_sdk::Address,
)
fn config_whitelist(
env: soroban_sdk::Env,
user: soroban_sdk::Address,
merchant_whitelist: soroban_sdk::Address,
)