The Snowflake is officially supported by OHDSI tools since September 2022 and starting with ATLAS/WebAPI 2.12 release.

Below is an example for connection to your Snowflake Instance from R code

# Download Snowflake JDBC driver
# https://docs.snowflake.com/en/user-guide/jdbc-download.html
 
install.packages("remotes")
library(remotes)
 
# Install DatabaseConnector and SqlRender
install_github("ohdsi/DatabaseConnector")
install_github("ohdsi/SqlRender")
 
connectionDetails <- DatabaseConnector::createConnectionDetails(
  dbms = "snowflake",
  user = "My_user",
  password = "My_password",
  pathToDriver = "/path/to/driver",
  connectionString = "jdbc:snowflake://my-snowflake-url.snowflakecomputing.com?warehouse=My_Warehouse&db=My_Database"
)
 
conn <- DatabaseConnector::connect(connectionDetails)
DatabaseConnector::querySql(conn, "SELECT * FROM MY_OMOP_SCHEMA.vocabulary")