Unfiled prior year returns

I am trying to find out the best way to file returns for 2022 , 2023, and the 2024 returns. When I was about to file my 2022 return in September 2023, my wife who had been ill for about 2 years was hospitalized. I spent every waking moment in the hospital with her until they sent her home with hospice. She died at home in October of 2023! Needless to say, I did not file our 2022 tax return. It was almost complete but I needed to get some info that she had prepared earlier in 2023. I have pulled that info up and trying to file Federal & CA returns! I had a health issue in the summer of 2024 that put me behind in filing 2023 returns which would have been a MFJ return with deceased spouse. I am working on 2024 now In all years, the government will owe me money as I deliberately over withheld on pensions and RMD's. Nevertheless, there are a number of questions that pop up for each year. It is my understanding that I will have to file paper returns for 2022 & 2023 to IRS and CA. On the 2022 and 2023, how will my wife's signature be handled? Do I sign it on her behalf indicating she was deceased in October 2023 & unable to sign 2022 & 2023 returns? How should these returns be submitted? Do I send a cover letter explaining situation, copy of her death certificate? Do I send Certified mail? Thank you -Gary S. Foy [email address removed]