Thank you for reaching out to the Wefugees community.
In my opinion, if the internship is part of the vocational training, no separate permit is required.
Please feel free to contact me again. In case you need a confidential consultation you can also write me at mbeon, which provides advice for adult immigrants in Germany via an app. Download the app at Google Play or App Store and get in touch with me or 160 other migration advisors. It's free of charge, anonymous, data secure and you can get advice in 15 different languages. Find more information here: www.mbeon.de