Typically 1-5 business days when it works properly.
...(Opinion?) :but don't do it.
Pay software fees with a credit or debit card.
We get hundreds of posts in here every year of people whose refunds get mis-layed...mis-directed...sent back to the IRS...for any number of reasons never worked out.
Just pay upfront,
____________*Answers are correct to the best of my knowledge when posted, but should not be considered to be legal or official tax advice.*