Experience with visa from the Dominican Republic?

Hello everyone,

We would like to invite our daughter's friend from the Dominican Republic to Germany this year, whom she met during her volunteer year in 2022/2023.

Can anyone give us any tips? Her boyfriend is studying, for which he is working hard on the side, and is expected to graduate in 2025. He has no assets, but supports his mother financially, but this is done in cash because his mother does not have a bank account.

1. What are the best arguments to use or what are the best arguments he can use to get the embassy to approve his visa? A declaration of commitment from our side is in the works.

2. Is it irrelevant whether our daughter writes the invitation letter, or should we as parents do it?

We are grateful for any tips!

Thank you!