ACH transactions (/issue and /redeem) may be up to $100,000 USD (10,000,000 SILA) per transaction for Starter, Launch and Growth customers. The max for Scale and Enterprise customers is $99.9MM per transaction.
Note this is only for ACH transactions. There is no max for /transfer (ie moving money between digital wallets).
If you need higher transaction limits, please contact sales to see if that can be accommodated.