This is a note that is already shared with my wife to help her through when/if I should die. I store it in a vault in 1Password so my wife can see this at any time and I try to keep it updated. I'm posting this publicly so maybe others can use this as a starting point so their spouse knows how to get into all the digital accounts/persona's we have (financial or otherwise).
The PIN to my phone is ... (I hope your spouse already knows how to log into your phone)
For some of these instructions, they might be a bit technical ... or ya know, you just lost your husband and don't feel like going through this. But for help in getting these things in your control so you know how to access them. For technical help I would trust Joe Name or Suzie Name, their contact info is in my phone. I would trust them to help you get these where you can access things.
My Gmail password is in 1Password as well. You might need to use this. I have Two Factor Authentication (2FA) turned on so you will need to use the Google Authenticator App to log into some sites. If something were to happen to my phone as well. The restore/backup codes for the Authenticator App is in 1Password as well.
Call TDAmeritrade and close out any positions that you do not know about. Some positions will be long term holdings, like IWM (Russell 2000) or SPY (S&P 500). But if you do not know ones, then close them out. I could have open positions that are short term and haven't discussed with you.
I have some cryptocurrencies in my Exodus/Coinbase/Meta wallet. I can't say exactly how to do this because their instructions are likely to change. The PIN and secret codes are in the shared note "Exodus Wallet" https://support.exodus.io/article/142-can-i-use-the-same-exodus-wallet-on-multiple-devices#
For Twitter - this is your call. You can delete my profile or leave it. If you want to leave it, then maybe post a tweet so others know that I kicked the bucket: "This is Chad's wife, I wanted to post to let you know Chad passed away recently ... funeral is at ... his obituary is at ..."
Github - This isn't anything particularly for you, but for other people online. This is most/all of my source code. I can specify a successor, so who ever I have named can get access to all of my code. You will need to follow their "deceased user policy" ... currently at https://docs.github.com/en/github/site-policy/github-deceased-user-policy
Facebook - You can send Facebook my obituary and Facebook will turn my profile into a "In Memory Of" profile. LinkedIn - You can send LinkedIn my obituary and LinkedIn will turn off or "delete" my profile.