"I recently converted a traditional Roth to Backdoor Roth"
Since there is no such concept with IRAs, it is not clear what you think you did.
Only a Traditional IRA, can be converted to a Roth IRA.
Assuming you mean Traditional IRA to Roth IRA,
Enter your 1099-R, hit CONTINUE then tell TurboTax you converted the amount to a Roth.
If you did this in 2021, your conversion is taxable,
so make an estimated tax payment of 22%, or whatever your top tax rate is.
There's no concept of capital gains in an IRA.
if you have a basis your basis-not-taxed is prorated against your total IRA value.
