B2B authentication best practices

I’m in the process of developing a B2B (business-to-business) application. I’ve implemented JWT auth, and it is working as expected. Right now the authentication functions as if it were a B2C (business-to-customer) app.

I’m trying to determine the best practices for B2B authentication.

Is having one authentication account bad practice in a B2B app? For example, every employee at Company A would use the same set of login credentials.