Where can I find the replacement fitting for the end of the brake line.

We're is the line running from, could be a union fitting

The line comes with both fittings on it, one for each end. Is it the wrong size? Does either end fit the car at some point? Now, did you slid a fitting to each end of the line before bending it? The part label holds both fittings on one end of the new line, you have to remove the label then slide the fitting to the other end, BEFORE bending it! Adapters are available @ parts store if needed.