Covid-19 has become a part of our lives since March 2020. Restrictions have almost disappeared and are now, generally, the same across mainland France. They may differ in the Overseas Departments and Territories.
French Ministère de l'Interieur's Coronavirus information page now indicates that no Covid-related documents are required to enter France from another non-EU country, including the UK. Similarly, and since 1st July, Eurotunnel no longer requires the upload of the vaccination certificate before travelling from Folkestone to Coquelles.
For travel from France to the UK, go to the Planning to travel to the UK? page on this website.