Premium SMS (or 19 SMS/MMS) services are information or entertainment services or downloads for your mobile phone or mobile-enabled device. The premium service provider charges you a fee for the premium SMS/MMS, which is then billed on your mobile phone bill.
Path:
realme UI 7.0 & 6.0 & 5.0 & 4.0: Settings > Apps > Special app access > Premium SMS access.
realme UI R & T & U Edition: Settings > Apps & notifications/Apps > Special app access > Premium SMS access.
realme UI 3.0 & 2.0 & 1.0: Not supported
realme UI S & Go Edition: Not supported