Connect PowerBI to SQL Server - TrustServerCertificate

Sorry this last post was so brief and cryptic, but I'm glad some people were able to interpret it and get it to work.

This is a PowerShell command to set an Environment Varible. In this case, it is setting a User Environment Variable instead of a System Environment Variable ("User" is not refering to a specific user account name, it is simply "user" as opposed to "system"). System Environment Variables generaly need a high lever of access to set, but most of the time, you should be able to set a User Environment Variable for yourself. 
The variable name is "PBI_SQL_TRUSTED_SERVERS." 

Open a PowerShell console window, and run this:

[System.Environment]::SetEnvironmentVariable('PBI_SQL_TRUSTED_SERVERS','<servername>', 'User')

Where <servername> is the name of the SQL server.

You should also be able to use wildcards (*) with domain names, like "*.example.com" which would match any servers that have a Fully Qualified Domain Name that ends in .example.com:

[System.Environment]::SetEnvironmentVariable('PBI_SQL_TRUSTED_SERVERS','*.example.com', 'User')

And as tralala2 points out, you should probably reboot after setting the environment variable.