I am in the process of migrating from Oracle to Postgres with Ora2pg but I find this problem that the signatures on the Postgres side do not exist
can you help me find the right solution ?

What will be equivalent of following oracle’s query in Postgres?

case
        when varSqlSignature = '1239678541' then 
            execute immediate varSql using 
                 /*1*/rowData.CODE_MOUVEMENT        ,/*2*/rowData.TYPE_CALCUL           ,/*3*/rowData.MONTANT_CALCUL
                ,/*9*/rowData.MONTANT_CALCUL_DV     ,/*6*/rowData.DATE_CALCUL           ,/*7*/rowData.CHAINE_CALCUL
                ,/*8*/rowData.RESULTAT_CALCUL       ,/*5*/varActionType                 ,/*4*/varLoadDate       
                ,/*1*/rowData.CODE_MOUVEMENT
            ;