Hello,
Adding a business account to Windows is different than adding a personal Microsoft account. It follows different procedure.
First of all, you need to make sure your computer is running Windows Pro edition, If it is Home edition, then you won't be able to add a business account.
If you have Pro, to do so, go to Settings > Accounts > Access Work or School, click on Connect.
Don't sign into your work email yet. Instead, click on "Join this device to Microsoft Entra ID". On the next step, you will be prompted to sign in, then you can sign in.
Once done, restart the computer and you can use "switch user" to sign in using the business email.