Can I transfer $ in a rollover IRA to my Roth IRA to meet my yearly Roth IRA contribution of $8000?

Hello,

I am 66 (and retired) and in 2023, I transferred all the money (~200k) in my employer sponsored 401k and 4757b to a "rollover" IRA at Fidelity.  I wanted to make my yearly contribution to my Fidelity Roth IRA for 2024, and was wondering if I can use funds from the rollover acct ? The funds in my rollover IRA are pre-tax, so I'm not sure if there is a way to do this? thanks for any help - appreciate it! Steve