Nothing about this involves a distribution or Form 1099-R from a Roth IRA.
You do have a Form 1099-R that includes the distribution that was converted to Roth. It has $125,000 in box 1.
Delete and reenter this 1099-R. Indicate that none of this Form 1099-R was RMD (because RMDs were waived for 2020), indicate that you moved the money to another retirement account, indicate that you did a combination of rolling over, converting or cashing out, then indicate the amount that you converted to Roth.
To reach the page that asks for your year-end value in traditional IRAs, click the Continue button on the page the lists the 1099-Rs that you've entered.
For your estimated taxes, if you have the cash available to do so, you can always overestimate your Q1 payment and adjust your Q2 payment to bring your total for Q1 and Q2 to only the amount necessary to satisfy the safe harbor. It just means that you pay a little bit 2 months early.
