Opensearch Dashboard - Data source creation failed

Versions (relevant - OpenSearch/Dashboard/Server OS/Browser): Opensearch Dashboard 2.14

Describe the issue:
I am gathering metrics data from OTEL, which is then ingested into DataPrepper. I use the following Metric Pipeline in DataPrepper to feed the data into Opensearch. However, when creating the DataSource in the Opensearch Dashboard, I encounter an error, even though the connection test is successful.

Also please help me how we can create a metric Visualization for the metrics that are collected from Otel

metrics-pipeline:
source:
otel_metrics_source:
health_check_service: true
ssl: false
buffer:
bounded_blocking:
buffer_size: 1024 # max number of records the buffer accepts
batch_size: 1024 # max number of records the buffer drains after each read
processor:
- otel_metrics:
calculate_histogram_buckets: true
calculate_exponential_histogram_buckets: true
exponential_histogram_max_allowed_scale: 10
flatten_attributes: false
sink:
- opensearch:
hosts: [“https://:9200”]
insecure: true
username: “admin”
password: “XXXXXXXX”
index_type: custom
tempalte_file: “templates/ss4o_metrics.json”
index: ss4o_metrics-otel-%{yyyy.MM.dd}
- file:
path: /tmp/otel_metric_data.log

Configuration:

Relevant Logs or Screenshots:
I am using opensearch IP:9200 in the endpoint URL filed