You want to do a backdoor Roth conversion or you just want to convert your tIRA to Roth IRA? The backdoor is a specific maneuver that requires all pre-tax IRAs be empty.
I’m going to guess you want to convert your tIRA to Roth IRA. If your tIRA contains only pre-tax dollars, you’ll owe tax on the full amount converted to Roth. If you have a mix of pre-tax and post-tax dollars in the tIRA, you’ll be subject to the pro-rata rule when converting, which means you’ll owe tax proportionate to the pre-tax dollars that are in the tIRA.