I over contributed to Roth IRA. I'm applying for excess contribution with my plan administrator (Fidelity). Should I ask them to withhold taxes or have Turbotax do it?

I over contributed to Roth IRA. I realized this when I noticed my AGI while filing my returns. I have applied for extension and bought some time. Now I am filling up the excess contribution form from my Roth IRA plan administrator (Fidelity). It gives me these options for paying taxes on earnings-

1. Have them withhold taxes at a certain percentage specified by me,

2. Ask them not to withhold anything

Which one of them should I select? 

My understanding is that it shouldn't matter because in either case, those details would be there on my 1099-R. Whether I paid taxes on my Roth earnings or not, Turbo tax would be able to read it from my 1099-R and take that into account while calculating the final refund/debt. 

Can you confirm if that's correct?

Thanks!