backdoor Roth Conversion

I'm 71 and retired and have an existing 6 figure IRA. I took $25k from this IRA and converted it to a Roth IRA (a backdoor IRA?) I also cashed out about 20K from the same IRA during the year. My single 1099R only shows the $45k total withdrawal. How do I enter this in TurboTax?  When I try to go through the "IRA Contributions" section, I'm getting a message that says i've exceeded the contribution limit.  Thanks for the help.