Custom Connector: Blank/Missing Credentials and issues with Incremental Refresh

Hi everyone.

I have a custom connector that requests my company's external apis and transform/populate a .pbit automatically for me.

In the images below you can have a grasp of how it is all made:

Using the desktop PBI app I get the data correctly without an issue.

However, after setting the parameters, filters and publishing the file for refreshing in the PBI service I get the following errors like in the image below:

Anyone ever had a similar situation? Appreciate any advice