so I've been trying to use JSForce to authenticate into SF. I used both the first example with SOAP API login and the second one with OAuth2: https://jsforce.github.io/document/#connection
However, I keep getting the same error each time:
XMLHttpRequest cannot load https://login.salesforce.com/services/oauth2/token. No 'Access-Control-Allow-Origin' header is present on the requested resource.
Any help? The account credentials used to authorize are a system admin, so permissions shouldn't be an issue, and I have the redirect URI as
redirectUri : 'https://login.salesforce.com/services/oauth2/authorize'