Where do I get the link to connect my broker institution with my turbo tax account?

What are you trying to enter?  First you go to the entry section for the kind of document you are trying to enter, like a 1099R or 1099B, and there you will see an option to import the data from your financial institution if that bank or brokerage etc. is partnered with TurboTax to allow you to import data.  If it is on the drop down list, then after you click on it, you will need to use the same user ID and password you normally use on that site to get the data to import to TurboTax.

If your financial institution is not on the list then choose the option that says I will enter it myself, and key the data in manually.