Please see
https://docs.databricks.com/dev-tools/api/latest/scim/scim-groups.html
An example
curl -X PATCH -n 'https://test-fw-us-1.cloud.databricks.com/api/2.0/preview/scim/v2/Groups/4062877510650442' -d \
"{ \"schemas\":[\"urn:ietf:params:scim:api:messages:2.0:PatchOp\"],
\"Operations\":[{\"op\":\"add\",\"path\":\"roles\",
\"value\":[{\"value\":\"arn:aws:iam::557839012409:instance-profile/shard-demo-s3-access\"}]
}]
}"