Similarly to how it’s done in those EU countries where foreigners can vote in local elections but not at higher levels: ID which indicates nationality. Spanish driver licenses now do, specifically in order to make them usable as voter ID; the other documents which are valid as voter ID in Spain already had nationality (one of them the passport - you can vote with a foreign passport from any EU country, once you’ve registered as a resident).
Civil rights are the minimum required by law. I think there’s a good case to make that we should extend the vote much further than that.
Like, people with kids in the public school system have an obvious interest in the school board. People who are legal residents have an obvious interest in the municipal goings on.
And who is a “taxpayer” is kind of fuzzy and an awkward standard on which to base rights. Is someone who rents a house less of a taxpayer than someone who owns one because the property tax that’s paid is one level removed?