Roth 401k employer match is trad. Plan offers option to convert the trad to roth as an in-plan conversion. I got 1099-R with code box 7 G. How do I file this on Turbotax?

I have a Roth 401k, but only my contributions go in as Roth and my employer match goes in as traditional dollars.  The plan offers an option to convert the traditional dollars to Roth with an in-plan conversion, and I did a conversion for the amount that had built up over a couple years of contributions.  I received a 1099-R form with the full amount of the conversion listed in box 2a as taxable amount, but the code in box 7 is G.  I thought G means a non-taxable rollover, why isn't this a code 2?  I'm not sure how to pay the appropriate tax for this conversion based on the 1099-R that I received. This was NOT a rollover to an IRA, this was entirely within my 401k from traditional dollars to Roth dollars. Also, how would I file this on Turbotax Deluxe?