This has been a tricky situation.
"The red B suggests that the IRA/SEP/SIMPLE box is also marked. A proper Form 1099-R cannot have both a code B in box 7 and the IRA/SEP/SIMPLE box marked. "
"In the follow-up questions to entering a code 2B Form 1099-R, make sure that your answer that the distribution was NOTfrom a Roth IRA."
-dmertz
Much of the conversation in this thread is irrelevant to you. https://ttlc.intuit.com/questions/2999639
In this case, the codes are B and G, not 2 and B. The question referenced above probably doesn't provide useful information in this case.
No, you cannot report this with only code G. You must select code G in one of TurboTax's box 7 drop-down boxes and code B in the other.
Codes G and B together indicate a direct rollover from a Roth account in a 401(k), 403(b) or 457(b) plan to a Roth account in another 401(k), 403(b) or 457(b) plan. It also implies that has nothing to do with a Roth IRA. In the follow-up, make sure to indicate that the IRA/SEP/SIMPLE box is not marked and that the taxable amount is zero. You should not be seeing any question asking if the distribution was from a Roth IRA; this distribution was not from a Roth IRA.