The bulb is likely an HIR2, which stands for 'halogen infra red 2'. Alternatively referred to as a 9012.
Utilised in some models of Vauxhall Insignias and Amperas. Additionally, there are a few compact Toyotas available, such as the Yaris. It is rather uncommon. If I recall correctly, Halfords did not have these in store until around 5 years ago.
The ECP pricing seems to be on the higher side.
If you can endure the delay, I would recommend making the purchase online.
I would get a pair since they often malfunction in rapid succession, and the "brighter" ones (regardless of the brand) have a much shorter lifespan.
The initial equipment mostly consisted of Philips, with Toshiba being a secondary option. Philips manufactures many sorts of products with varying intensities. If your items are authentic, they will most likely be labelled as Philips LL. I understand this to imply an extended lifespan (with typical magnitude).
The Optibrite bulbs, manufactured by Philips, are supplied by Toyota dealers. However, it is worth noting that these bulbs have a stated life expectancy of just 500 hours.
It is likely that you have discovered that a single bulb is responsible for both high and low beams, achieved by a mechanism including a solenoid-driven mechanical shutter. Therefore, the malfunctioning of a single blown bulb has resulted in the failure of both beams in that headlamp. If both lights fail simultaneously (based on personal experience!), it may be rather unpleasant.