Please make sure you are not confusing the packed-in Jump Force Ultimate Edition code with the retailer-exclusive and separately provided DLC code/voucher for the Pre-Order content.
Since the Pre-Order content is not sold separately, it will not show up on any of the digital stores (PSN, Xbox Live, Steam etc.) as a manually downloadable item. This content will only appear in-game within the "Customize Avatar > Tops" from the in-game menu or from the "Vehicles" option that is reached by pressing down on the + (directional pad) while in the Lobby/Hub.
If the content is not located in the above-mentioned locations, it's possible there may be an issue with the license for this content not applying properly to your profile/account. Very often this occurs when products are imported from a different region and a voucher/code is provided from an incorrect region (as all DLC content is "region-locked" and can only work properly when used in conjunction with a same-region game disc).
In these types of situations where the issue is with the account/profile or licenses to DLC content not properly being tied to your account, you will need to contact the first party's support teams (Sony, Microsoft, Valve/Steam) for additional assistance. Only the first parties have access to player accounts/profiles through their platform and would be able to check to ensure the license is properly applied to your account.
1st Party Support contact info:
Sony PSN Support: 1-800-971-7669
Microsoft Support: 1-800-469-9269
Steam Support: https://support.steampowered.com/