Hooking your iPhone to your TV with a wired HDMI connection isn’t as convenient as casting from your phone to the TV, but wired connections do offer a more reliable streaming experience.
The simplest way to physically connect your iPhone to your TV is to use an HDMI cable from your phone to your TV’s HDMI port. You’ll need an iPhone-to-HDMI cable adapter to connect the HDMI cable to your iOS device. It’s called a Lightning Digital AV Adapter. You can get it direct from Apple for £49.99.
The above link will also show you some third-party knockoffs priced as low as £13.99. Apple, of course, always recommends that you buy its products for optimal compatibility, but the third-party versions will get the job done and save you a good chunk of change. Just make sure it supports High-bandwidth Digital Content Protection (HDCP).