Hi again,

Our theme already supports this requirement.

Step 1: Go to Template -> Add section -> Add content to this section.
Step 2: Go to edit product -> Tab Organey settings -> Size chart -> Select Section Content created in step 1: https://ibb.co/LCHdwBz

The content will be displayed when you click on the Size chart: https://ibb.co/9YVXvTn