I got a cp59 notice that I didn’t file my 2023 taxes. I was living in Alaska at the time. I live in Washington now. Can I just ignore it?

The CP59 notice is in regard to your federal return---which the IRS is saying that you did not file.   Although you were in a state with no state income tax, you were still subject to federal tax.   The IRS wants a federal return from you.  Did you prepare a 2023 federal return and file it?   Or was it rejected?

https://www.irs.gov/individuals/understanding-your-cp59-notice

Did you file a federal tax return?  You still file federal every year even if your state has no income tax.