It can take some time, commonly 21 days, for the IRS to process your tax return. Currently, the IRS is backlogged. Try waiting up to a few days before the May 17 deadline before prompting a secondary means of payment. Otherwise, it could end up that you double pay and then have to wait for a refund.
To determine if there is a problem, check your account here: IRS: View Your Tax Account Information.
If the payment has still not been withdrawn and you are within a few days of May 17, go to IRS Paying Your Taxes for options or see 2020 Form 1040 Instructions, page 62. Payment options include:
