Prepaid electric key meters

Read an interesting article I will put a link hopefully that is allowed. When we moved into our house it had a key meter for the electricity which we have never had changed. In the article, if you charge your key up and put it on the meter before the 1st April until you recharge the key and put it on the meter after the 1st April you will still be charged at the old rate. I realise many people can't maybe afford to put extra credit on but worth doing if you can. www.moneysavingexpert.com/news/2022/02/prepay-for-your-energy--you-could-keep-today-s-cheaper-rates-for/