Formally - it is necessary, since a visa-free visit to Tunisia is possible under the condition "to arrive in the country by a direct flight", in this case we are talking about a transplant. In practice, they do not find fault with this - it is enough to have a voucher for servicing. In the winter, for example, when there are no direct charters and "regulars", flights with a transfer in Europe are the only way for tourists to arrive in Tunisia.

The voucher can not be purchased directly from the hotel, it is a document issued by the tour operator. The hotel provides a confirmation of the booking (or payment) of the accommodation. With this confirmation and the package of documents mentioned on the page of the visa to Tunisia, you must apply to the Consular Section of the Embassy of Tunisia in Moscow for a visa