Welcome. I input my fuel in price per litre and number of litres purchased. I have Settings set for UK(litres, miles, UK MPG). This allows me to enter current odometer reading in miles, cost per litre and either total cost or total litres.
You could do the same. However, if you put the price/litre in Euros the cost would be in Euros but with a £ sign. As long as the price per litre and total price is in the same currency, the numbers work.
Here is my Add A Fuel Up page.
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