ShippingEasy link with WooCommerce

I don’t know what to do anymore. I spent 2 days and a half trying to figure this out.

My issue: can’t get the shipping rates from ShippingEasy to show up on my website.

Steps already taken:
Website is basically ready with WordPress and WooCommerce.
ShippingEasy account created.
ShippingEasy account showing as linked with WooCommerce, there was a WooCommerce page that showed up for me to approve the connection, I approved it.
The REST API from ShippingEasy shows up in the WooCommerce settings.
Checked to see if there are any WooCommerce extensions from ShippingEasy and there’s nothing on the marketplace.

I already tested directly with the WP USPS plugin and it shows the shipping rates on my website, but when I disable the USPS plugin, no shipping rates from ShippingEasy show up.

I even tried installing the old WP ShippingEasy plugin and nothing.
Btw, everything is updated to the last versions possible.

Please, help…