Amazon Prime Gaming currently lets you claim Battlefield 4 for free if you have an Amazon Prime subscription.
The offer is available until June 21st 2021 and if you dont have an Amazon Prime account yet, you can claim a free month here.
Battlefield 4 standard edition - For a limited time only, get a code to claim the game on Origin for free. This offer is applicable to PC only. Amazon Prime members have the ability to claim one game code for Battlefield 4 Standard edition until 21st June 2021. The code will be eligible to claim on Origin until 21st July 2021.