The ACLU has a petition to get Congress to pass a law requiring all states to allow vote-by-mail, like Colorado, Oregon, Washington, and other states already do. After you sign it, they will automatically send a message to your congressperson and senators.
This is to avoid the disaster that just happened in Wisconsin, with people putting themselves in danger in order to vote. Dozens of Wisconsin voters and poll workers have tested positive for COVID-19 after their recent primary election, where over 400,000 people voted in person.
The US Supreme Court blocked an effort by the Wisconsin governor to expand their absentee voting system.