The connection dialog is explained here.
In the connection dialog you can choose the 'Edit Manually' in the JDBC URL combo or 'Standard'. The 'Edit manually' will let you edit the JDBC URL by your wish.
Log in the Snowflake console, check the Accounts and hover the account link. Copy the account in the Host field.
Copy the account into the host filed and fill in the user credentials. If you use the 'Edit Manually' in the JDBC URL combo, fix the URL string with the account location.