If you are a US citizen living outside the US, you are still able to vote!
Register to vote abroad and request your ballot at the links below
If you want something with a decent UI: https://www.votefromabroad.org/
If you want to use a .gov site for trust: https://www.fvap.gov/citizen-voter
Also on another note, democrats abroad have an offical mastodon account
Nice! Make sure to do that sooner rather than later since it can take a bit of time for the ballot to get back