I do not know how to proceed to file for my CNF (certificate nationality french )

I do possess an EXTRACT DE NACENCE for Augustin Lafont dated 1780 from the St. Etiene Diocese, Toulouse,France, which is written in French and I need help to find my ancestor past so I can apply for my CNF. I have found his death date foe 15 Nov. 1872 and also under FRANCE, HAUTE- GARONNE, TOULOUSE, CIVIL REGISTRATION, ( 1792- 1893 ) AUGUSTINE LAFONT 1872 with a list of all my relatives . The issue is I do not how to proceed to file for my CNF (certificate nationality french ).

Please need all the help possible so I can apply for it.

Sincerely,

CHARLES R. LAFONT JR