Read before you start
Have you already tried to add an app block into you theme? If this option did not work, you may try to add a CSS class, else, we recommend to check adding an app block instead.
If you had an app block but you really want to you CSS Class (not recommended) you will need to delete the app block in your store's theme.
Step 1
Open your store and navigate to a product page. Right-click on the page and select the option 'Inspect'
Step 2
Click on the selector icon
Step 3
Hoover over the target component (the button will be placed right below the target component).
Step 4
Click on the component and check the code on the right pane. The relevant CSS class for this component will be selected. Copy this class (text contained between brackets ''").
In the example below: price price--large
Step 5
Open SmartSize and navigate to Settings. In the section 'Manual placement' click on '+ View manual options'
Step 6
Under Option 2: CSS Class, paste the CSS Class that you have selected: price price--large and click 'Save'.
Step 7
Verify the new position in your store.