This link explains how to create dual axis on tableau so charts look like this
but when I try to re-create this, all I get is the below. Where do I right click to select "Synchronize Axis"
Drag the [Curve]
pill to the right side of the bar chart. You'll see a black dotted line appear where the axis ought to be. Drop the pill, and a second axis will appear. (Equivalently, right click on either measure on the rows shelf and check Dual Axis.)
Right click on that new axis and click "Synchronize Axis".