If you already have Telegram installed, go to your phones web browser and search for
'FE Partalert Telegram', hit the link and Telegram will automatically open and allow you to follow/join the FE Part Alert group and thats it. As long as you have notifications turned on in the Telegram app you'll get a notification when an alert comes through so all you have to do is hit the link for the GPU you want and it'll open the UK website for the GPU and if you are quick enough you can hit the add to cart button and off you go.
Keep on spamming F5 for about 30mins after the you get the alert because apparently as people fail payments and/or exceed their 1-per-customer limit the cards that they had temporarily held for them in the carts slowly get put back on the website again and are then up for grabs.