An error occurred while saving the commentRobert Duke commented
This used to be able to be accomplished by saving an individual message from an existing chat, but new versions of Teams have created a new "Saved" list.
My workaround is to start a new Teams meeting Titled "Notes to Self" with just myself as an attendee. Once in the meeting send a single chat message and you will then have the chat history available to you in Recents.
That being said, it would be nice to simply be able to simply add a "Note to Self" option.
The engineering team is continuing to work on adding support for multiple accounts on desktop clients. We will first launch support for 1 work/school account and 1 personal account so users can enjoy Teams for work and personal side-by-side. Windows and MacOS. Support for multiple work accounts is still being worked on and will come at a later date.
You can track status via the roadmap here: https://www.microsoft.com/microsoft-365/roadmap?searchterms=68845.