Any elected or appointed municipal officer, deputy, assistant, or an employee of any municipal corporation may attend, at the expense of the municipal corporation, any conference or convention relating to municipal affairs, if authorized by the mayor, the chairman of the commission, or the city manager of such municipal corporation, and, if the fiscal officer of the municipal corporation certifies that funds are appropriated and available for such purpose, such person shall be reimbursed for his expense so incurred.
A request for such allowance shall be made in writing to the mayor, the chairman of the commission, or the city manager showing the necessity for such attendance and an estimate of the costs thereof to the municipal corporation.