You can install Yandex Go on your phone. If your phone is set to French, the app will automatically switch to French. You can create an account using your phone number.
The main menu is accessed by tapping the three bars in the top left corner:

This opens the following page:

In "Paramètres" (Settings), you can change the app language:

Otherwise, you select your country and phone number to create the account:

Once the account is created—after SMS code confirmation—the "Mode de paiement" (Payment method) option in the middle of the main page list (second screenshot) becomes active. You can select cash payment.
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Foreign SIM cards are inactive for internet during the first 24 hours after entering the country (Russian SIMs also face this after returning from abroad, unless you go through a simple immediate reactivation process). However, there’s usually an exception for essential apps like Yandex Go and Yandex Navigator.
That said, if you’re using a foreign SIM, you’ll incur roaming charges from your carrier. If possible, check if the station’s network still works in the bus arrival area. You won’t enter the building but will head straight outside.