According to what is established in the Law 20,960, Chileans abroad may participate in the referendum convened in Chile by April 2020, in order to determine whether citizens agree to initiate a constitutional process to generate a new Constitution, and determine the mechanism for said process.
For now, it will not be possible to vote from abroad for the election of the so-called constituents, which is set for October 25, 2020 because that would have to be approved by an enabling bill.
How to vote abroad?
If you are Chilean and you are not registered in the Electoral Registry you can request your incorporation at the Chilean Consulate in Amsterdam. And if you were born abroad, but you are Chilean, to request your incorporation you must have lived in Chile for more than 1 year.
If you are registered in the electoral register with a Chilean address you must change you electoral address to your current one in the Netherlands on the website of the Electoral Registry SERVEL. For that you will need to have your personal electronic code (it’s like the Dutch DigiD). If you don’t have it you can obtain it at the General Consulate of Chile in Amsterdam. In that diplomatic headquarters you can also make the change of electoral address in person. To do this you must present your identity card or Chilean passport.
Address changes may be made until the enactment of the decree calling the referendum. That date does not depend on Servel, so therefore they are telling everybody to register or make the change of electoral address during the month of November.
More information: https://www.servel.cl/solicitud-de-cambio-de-domicilio-electoral-para-chilenos-en-el-extranjero