If you are opening the product from your web browser (Chrome, Safari...):
1- Open the product in your browser and tap the Menu button as shown below.
2- Choose Share...
3- Choose Copy.
If you are opening the product from the brand's own app:
1- Open the product page within the brand's app and tap the Share button.
2- If a Copy button shows, tap it.
3- If a Copy button doesn't show, tap the Menu button (usually a " . . . " icon).
4- Choose Copy on the new page.