Undocumented immigrants (also known by the bigoted term of illegals) are not voting in federal elections. There are no numbers because it is not happening in any scale to actually affect an election.
1/
"The Brennan Center for Justice, a liberal group, surveyed 44 election officials in some of the most populous and immigrant-heavy jurisdictions in the country after 2016, including Arizona, California and Texas. It found only about 30 incidents of a possible noncitizen voting out of 23.5 million votes cast in those places." - Source: AP News
2/
After the 2020 election, cases filed by Trump's team were brought to judges, including many judges appointed by Trump. Most were dismissed on procedural grounds, but some were dismissed for lack of merit.
3/
Upon review of a list compiled by The Heritage Foundation, a conservative group, of election fraud cases that resulted in conviction, since 2020, most illegible voting convictions were because a released convicted felon did not have the right to vote, or a US Citizen voted at separate addresses. (This can happen when someone moves to a new state and does not change over records, thus erroneously voting in two different jurisdictions.)
4/
Don't believe things just because a politician spews something at a podium.
BTW - It is legal for undocumented immigrants to vote in local elections if the jurisdiction allows it.
5/5