How do I report the sales of stock or bonds? I don't have a 1099 B covering my RMD.. Only a 1099 R

You are correct, your RMD is reported on Form 1099-R and does not involve a Form 1099-B. 

It is possible that you had a Form 1099-B that carried over from last year.  To review your forms in the investment section of TurboTax, please follow these steps:

1. Login to your TurboTax online account and click on Pick up where you left off
2. On the left side of your screen, click on Federal and then Wages & Income
3. Scroll down and click Edit/Add next to Investments and Savings (1099-B, 1099-INT, 1099-DIV, Crypto) 
4. From here, you can click on the trash can to delete the Form 1099B if you did not receive one this year

You do not report sales of stocks, bonds or mutual funds that occur within a retirement account (e.g., IRA or 401k). All you report is the "distribution", which is reported to you on a 1099-R and is taxed as ordinary income, not as capital gains. 

So, what sales are you trying to enter?  If it's from non retirement accounts, it would be unusual not to have a 1099-B, but the workaround is easy, if you don't.