The migration period to bring your characters from blizzard ended on December 1st 2020. The companies gave us 14months to transfers to steam. They notified us through various contact means like Twitter, email and so forth.
Hi there. Unfortunately nothing can be done at this time. The deadline to migrate was December 1st. If you wish to continue playing on PC, you’ll have to create a new character on steam. [quote]The account migration period from Battle.net to Steam ended on December 1, 2020, and can't be extended or turned back on. It's now impossible to transfer anyone's account, purchases, and characters over. From September 2019-December 2020, multiple emails, social media messages, and in-game notices were sent out to inform players that this was occurring. If your account wasn't migrated over, you will have to create a new account on Steam with new characters if you'd like to play Destiny 2 again.[/quote] https://help.bungie.net/hc/en-us/articles/360049498031-Destiny-2-Cross-Save-Guide