Probably the first, but there is no way of telling without any context. Without context, it could also be 'will confirm' or 'haven't been able to confirm'.
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
I confirm my costs would be between £1,500-£2,000 or I confirmed my costs would be between £1,500-£2,000 which one is correct?