Does anyone know how to add error bars to a line chart in excel?

Hello, I am working on assignment in which I have to create a line chart with markers that also displays error bars, which indicate the standard deviation. The error bars need to represent one standard deviation above and below the plotted mean. The exact instructions are as follows:

• Direction: Both
• End Style: Cap
• Error amount: Custom → Select the cell in which you calculated the standard deviation in Excel. You should select this cell for the positive and negative error values.
• Line: Solid line
• Color: Black
• Width: 1 pt

The videos that I have found show that, once you select the chart, you should see an option in the ribbon to "add chart elements" and "error bars" is one of the following options, but I do not see that option in the ribbon. I have also looked in the chart format options, but I have not seen anywhere to add error bars.
Thanks in advance for any help or suggestions.