No such thing in germany.

Bullshit. You didn't understand my question. I'll rephrase and elaborate.

Not every issue is a national issue. You vote on issues in your locality that someone living across the country is not eligible to vote on. They vote on issues in their locality that you are not eligible to vote on.

For example, In my state, schools are funded at the district level through property taxes. I vote on the tax rate in my school district; someone across the state votes on the tax rate in their district. (Generally, districts and cities are at the same level, but sometimes two or more cities will combine into a single school district, so they are technically separate.).

Zoning issues are at the city level. I can vote on zoning issues in my city; I can't vote on zoning issues in another city.

We had a state-level abortion issue on my last ballot: individuals residing in other states were not eligible to vote on my state's issue.

My point is that you have similar need for registration, it's just done automatically alongside the process of getting your ID.

Generally, we register to vote in the same process as getting or renewing our ID cards. That first ID card might be a driver's license issued at 16, a learner's permit at 15, a moped license at 14. Passports and state IDs can be issued at even younger ages, but we are not eligible to vote until 18. Our first ID generally doesn't include voter registration, simply because we aren't yet eligible. People who turn 18 since the last general election will need to register separately.

Some people have dual residency. "Snowbirds" are retirees who spend their summers in a northern state, and the winters in Florida. They are only eligible to vote in one state or the other, but technically qualify to vote in either. We vote in November; these snowbirds will be in Florida at the time, and will need absentee ballots to vote in their northern elections. Absentee ballots are only issued to registered voters.