I did not transmit payment to the IRS yet; I have only filed the return through turbo... is there a way to still transmit payment instead of mailing it?

If you have federal tax due you can pay by mailing your payment with the 1040V voucher, having the payment taken out of a designated bank account, or you can pay directly on the IRS website.   2019 Federal tax due should be paid by July 15, 2020.

https://www.irs.gov/payments/direct-pay

Perfect response - thank you.