Enter this Discord server:
https://discord.gg/UGmQKuY7
Then access this chanel:
https://discord.com/channels/1130158543237030049/1146892703028760696
Scroll up a bit, you see "PS Bot" (the one with gold and black icon) hit "Get Started" button.
Then, in the chat it will create with you, type /decrypt, choose "false" for "include_sce_sys" parameter.
Then submit you save file for it to decrypt (the .bin and non-.bin files).
Wait for it to finish, and you can download a zip containing memory.dat wich is you decrypted save.
Download this tool:
https://github.com/alfizari/Elden-Ring-Nightreign-Save-Editor-PS4/releases
Then open memory.dat on it, then select a save slot, now you can modify the relics yourself.
After modding, you need to encrypt the save in the bot again before copying to yor console.