You would enter it as a charitable contribution. However, you cannot claim charitable contributions in TurboTax Free Edition. You would have to upgrade to TurboTax Online Deluxe or higher, or use any edition of the CD/Download TurboTax software, or use the IRS Free File Program delivered by TurboTax if you qualify for it.
You didn't say what level of membership you have. For any level higher than Family Plus the membership fee is not fully tax deductible. The academy web site gives the details.
You can only deduct a charitable contribution in the year that you paid it. On your 2019 tax return you can only deduct the membership fee that you paid in 2019. A membership that you paid in an earlier year would have to be deducted on your tax return for the year that you paid it.
For 2019 and earlier all charitable contributions are an itemized deduction. They will not reduce your tax or increase your refund unless your total itemized deductions are more than your standard deduction.