@FlowerPrince Please clear Edge's Internet Explorer-mode data.
https://support.microsoft.com/en-us/microsoft-edge/view-and-delete-browser-history-in-microsoft-edge-00cf7943-a9e1-975a-a33d-ac10ce454ca4
Additionally, move the entire Sims 3 folder out of Documents > Electronic Arts and onto your desktop. Open the launcher to spawn a clean folder, but don't try to sign in there. Just login to the Store, using Firefox, and see whether you can download and install one of your worlds.
Moving the Sims 3 folder will remove, but not delete, your saves and other user data. That can be addressed later; for now, please use the clean folder with nothing added to it.
If this doesn't help, please uninstall Sims 3 with Revo Uninstaller (the free version is fine), and the EA App as well. Before doing so, rename the Sims 3 folder that you moved out of Documents to something that doesn't have "Sims 3" in its name so that Revo doesn't try to delete it. Since this folder contains your saves, I'm guessing you'd like to preserve it.
Restart your computer before reinstalling the App, and install Sims 3 into a new folder you create specifically for this purpose. The folder should be on the root level of the drive of your choice, for example C:\Games is fine, but not C:\Program Files\Games.