It failed because I didn't have enough money in my bank. Will it automatically transfer as soon as I put money in?
No, the IRS will not make a second attempt for a direct debit payment, although the clearinghouse may do so.
The IRS will send you a letter explaining other payment options if the debit failed.
Here's more info on Will the IRS Retry an EFT?
Can I contact them to make the transfer again?
Is it a paper letter or an email?
Thanks for your reply