Step 1: Go to your Profile and select "Galleries"
Step 2: Select the "Create gallery" button
Step 3: Click on the content you want to add to a Gallery. The content will open in a modal. Click the "Save" button.
Step 3: Choose the Gallery that you want to add the content to and click "Save." If you don't have a gallery, you can click the "Create new" button to create a Gallery and save your content to it.