Where Can I Get Certified Copies of Documents for Master's Applications in the United States
Option (1) is probably easiest.
It's normal in the US to send official transcripts directly from one educational institution to another. The way you do this is typically to go to your school's website and search &quot;official transcript&quot;. You may need to pay a fee or may only need a fee to send more than some number.
Since schools are used to sending these to other US schools I'm sure they are also prepared to send them to Germany. They'll come directly from the university with some sort of seal.
When I was applying for grad school this step at least was still entirely by physical mail; there may be digital options now too.