You don't report a 5498 on your return. You should have a 1099R for that.
After you enter the 1099R it will ask you some follow up questions.
Pick I moved it to another retirement account. Then it will ask if it was to a ROTH.
Then choose - I did a combination of rolling over, converting or cashing out the money
Then it will ask how much you converted to a ROTH
The whole gross amount (before taxes) is 100% taxable. Then you get credit for the taxes withheld on 1040 line 25b.
You do not enter it under Deductions as a ROTH IRA contribution. A Rollover or Conversion is not a new contribution.