Yes, any 2021-2026 ZEB A1-A3 can be upgraded to Charger 3.1 RC2 by replacing the damper assembly with part number 00.4318.095.002 (Damper Upgrade Kit - Charger3.1 RC2 Crown w/ButterCups (Includes Complete Right Side Internals) - ZEB A1 + (2021-2026)).
If your fork already features a Charger 3 RC2 damper, then you can use part number 00.4318.096.000 (DAMPER UPGRADE KIT - CHARGER3.1 HEADVALVE/SHIM KIT(UPGRADES CHARGER 3 RC2 DAMPERS TO CHARGER 3.1) - BOXXER D1(2024-2026)/ZEB A1-A3(2021-2026)/LYRIK D1-D2 (2023-2026)/PIKE C1+(2023+)) to convert your damper to 3.1 RC2. All other dampers require the complete damper to be replaced.
RockShox service kits and spare parts are best obtained through your local shop or dealer. See our dealer locator, below, to find a dealer near you. If no one is currently listed near you, then please search for local shops via your preferred web browser.
https://www.sram.com/en/dealer-locator
Manuals and additional information about RockShox and SRAM components can be found at our service site, linked below.
https://www.sram.com/en/service
Further questions?
Reach out to Rider Support by Asking A Question at the link below.
https://www.sram.com/en/rockshox/campaigns/rockshox-rider-support