Should I enter amount on the 1099-R on line 5b on the1040-SR form? Thank you...

Depends what the 1099R is from.  It might go on line 4.  Just enter the 1099R exactly as shown and Turbo Tax will put it on the right line and calculate the taxable amount on the b line.

The easiest way to get to the 1099-R entry screen is to simply search for 1099-R (upper- or lower-case, with or without the dash) in your TurboTax program and then click the "Jump to" link in the search results.

Enter a 1099R under

Federal Taxes Tab or Personal (Home & Business)

Wages & Income at the top

Then scroll way down to Retirement Plans and Social Security,

Then IRA, 401(k), Pension Plans (1099R) - click Start or Revisit

If you are filing a Joint return be sure to pick which person it is for.

Don't enter the bank or broker name and don't try to import it.  It is just as fast and easy to manually enter it.  At the bottom pick -  Change How I enter my Form

Then on the next screen pick I'll Type it in Myself