Biometric Residence Permit
UK has moved to a digital immigration system and Biometric Residence Permits (BRP), Biometric Residence Cards (BRC) and passport endorsements such as ink stamps and vignette stickers in passports, have been replaced with an online record known as an eVisa.
Follow the link below for more information.
Government guidance regarding eVisas
After you have applied for an eVisa, you should keep your BRP for reference purposes even when it has expired.