i have solved it now. 3 days after me another user had a similar question: Import v1.x backup to v2.6 - #3 by FredAnna and the answer from user @Pooh pointed me to the right direction.
With Info from Upgrade from InfluxDB 1.x to 2.6 with Docker | InfluxDB OSS 2.6 Documentation i could upgrade my data from 1.x to 2.x
docker run -p 8086:8086 \
-v influxdb:/var/lib/influxdb \
-v influxdb2:/var/lib/influxdb2 \
-e DOCKER_INFLUXDB_INIT_MODE=upgrade \
-e DOCKER_INFLUXDB_INIT_USERNAME=my-user \
-e DOCKER_INFLUXDB_INIT_PASSWORD=my-password \
-e DOCKER_INFLUXDB_INIT_ORG=my-org \
-e DOCKER_INFLUXDB_INIT_BUCKET=my-bucket \
influxdb:2.6
