This error is normally seen when the endpoint URL is not correct.

Have seen this normally when you are appending https:// to the URL when the application does not require https:// appended.

Please check and confirm if the endpoint has https:// appended if yes please check after removing it.

Refer to the following document which talks about connecting to snowflake using Oauth.

https://community.snowflake.com/s/article/Connect-from-Power-Automate-Using-OAuth