Feeld is for people 18+ years of age. Real ages are shown on Feeld profiles, but not actual birth dates.
If you made a mistake on entering your date of birth, you can fix it within the first 7 days of creating a Feeld account by going to Settings > Edit Profile > Date of birth.
After the first 7 days, you cannot change your date of birth—if it is incorrect, you must contact support to change it.