RMD for 2020 was suspended. I withdrew about $77,000 from my IRA and converted it to ROTH. Is the $77K considered a RMD?

No RMD cannot be converted to a Roth. But RMD were waived in 2020.  

You must indicate to TurboTax that none of the distribution was RMD. If you already enter the 1099-R as RMD and changing your answer to the RMD question doesn't work then you have to delete and renter the 1099-R form. 

Please follow these steps to enter your 1099-R:

1. Login to your TurboTax Account 
2. Click on the Search box on the top and type “1099-R”
3. Click on “Jump to 1099-R” and enter your 1099-R
4. Continue until "How much was a RMD?" and select "none"
5. Answer questions until you get to “Tell us if you moved the money through a rollover or conversion” and choose “I converted some or all of it to a Roth IRA”

You can verify your entry by looking at your Form 1040 line 4:

1. Click on "Tax Tools" in the left menu
2. Click "Tools"
3. Click "View Tax Summary" in the Tool Center window
4. Click on "Preview my 1040" on the left