We do not provide a guarantee for cost... we offer the possibility for a job experience. We offer free accommodation as a benefit but we cannot take care for any additional cost.
So I do not know if you will get a Visa for Germany if there is no scholarship behind... normally they expect
Health insurance
Enough money or a cost guarantee from Germany
Invitation letter
Documentation where you will be hosted
Poorly I do not have much experience with the Embassy.
Best regards