need help

i have a file i was going to farm 100% of the achievements on, but did some googling & learned one of the updates gives you 3 relics from a crown upgrade, i did not receive them because i’ve already fully upgraded my crown. am i just stuck starting a new file to get these relics now, & will it give me the achievement when i acquire those 3 or do i have to farm all of them on a new file to get said achievement?