The FD-1 Hi-hat control pedal is included with the TD-02K and TD-02KV kits. If your FD-1 is malfunctioning or has been damaged, you can contact your local Roland Service partner or Roland Customer Support (Backstage) to have it repaired.
Rather than service, you can also consider replacing the FD-1 with the Roland FD-8 or FD-9. Either pedal is compatible with the TD-02.
https://www.roland.com/global/products/fd-9/
https://www.roland.com/global/products/fd-8/
The VH-10 or VH-11 hi-hat pads are also compatible, however they need to be mounted to an acoustic hi-hat stand.
https://www.roland.com/global/products/vh-10/
https://www.roland.com/global/products/vh-11/