Watson Amelia is a member of Hololive English. Her fans are called Teamates.
This hashtag represents the belief that Amelia will perservere and overcome any difficulty she faces. It’s somewhat of a meme because it’s used when Amelia repeatedly tries to do something with a low chance of success.
It was created when Amelia was playing The Outer Wilds and wanted to land on the Sun Station. This is difficult because it orbits quickly around the sun and any maneuvering mistakes can easily lead to crashing directly into the sun itself. When trying to land, her Teamates were split between telling her give up and spamming #AmeBeliever. After an hour, she finally landed on the station.