thank you for reaching out to us and for sharing your question with the Wefugees community.
First of, all congratulations that you have been able to apply for a "Beschäftigungsduldung". I deeply appreciate that you are preparing for the B1 test, because you will need a B1-certificate for your residence consolidation later. What you mentioned above is correct: After holding a "Beschäftigungsduldung" for 30 months you can apply for a residence permit according to § 25b Abs. 6 resp § 25b Abs. 1 Residence act. This also holds for your family members and it is the first step towards a further consolidation of your residnece rights here, like a settlement permit after five years of regular work and stay here, for which B1 is required (and a test about life in Germany, called "Leben in Deutschland"). So there is no need to apply for a humanitarian residence permit, which is, as a rule, being granted during an asylum procedure and not after a "Beschäftigungsduldung".
I hope my answers were useful for you and I'll be very pleased if you contact me again with further questions. I'm a member of the mbeon-staff and I‘ll be glad to guide over a longer period of time.
mbeon is an online advisory service for migrants via the mbeon-app, which you can download on your smartphone for free. You'll find me in the mbeon-app under my name München, Frau Müller and get confidential one-to-one advice in a safe virtual room where nobody can read messages. For further information please visit www.mbeon.de.
Download for Android: https://play.google.com/store/apps/details?id=de.zone35.mbeon
Download for iOS: https://apps.apple.com/de/app/mbeon-messengerberatung/id1408795643