How can i implement visitor Id on android APP? Overall steps

Hi guys, i'm newbie here, as you can see on title of my question, i´m a bit stuck on implementation visitor Id, i cant really understand how it works the configuration on development code, i created a new report suite as a first step on analytics, second i set it up the property on mobile services and activate the option "visitor Id service", but i cant see any value on custom variable correlated to this, so i´ve searched in documentation but just talks about Experience Cloud Id Service, i know there it is different services this and "Visitor Id", for now i'm just want implement just Visitor Id, also i´ve readed something about "s_vi" cookie, but without success to have a clearly way to implement on android (mobile apps).

Please any have some idea for getting start this development?

Thanks in advance and so glad to be here on the adobe community.