An initiator for initiating detonation in a detonation cord of a perforating system, where the initiator comprises a modular electronic igniter that quick connects into a portion of high explosive. The high explosive is disposed in a housing having an end of detonation cord crimped therein. The electronic igniter may be shipped to the field and/or stored separate from the high explosive then the two may be assembled just prior to deploying the perforating gun assembly in a wellbore. Various methods of quick connecting the electronic igniter to the high explosive may be used.