The UK is no longer in the EU. So we don't charge tax at the time of purchase. However you will be charged Tax which is usually 20% (correct as of 2022) once the parcel has arrived in France.
You will also be charge a admin fee by the courier to process the parcel through customs. This admin fee can vary depending on the courier and value of the goods. Generally you should expect it to be €5 to €10.
You will be contacted by the courier to pay for the customs fees when the goods are imported.
This is the same for any goods ordered outside the EU. There is trend of big shopping sites to allow you to pay for the tax in advance, we are looking at implementing a similar system as soon as we can (later in 2022???)