Pour the fruit juice and lemon juice into a medium saucepan and heat over medium heat until warm.
Gradually whisk in the pectin powder, ensuring no lumps form.
Add sugar and stir continuously until fully dissolved. Bring the mixture to a gentle boil for 1–2 minutes, then remove from heat.
Optional: Add flavor extracts or coloring and mix thoroughly.
Pour the mixture into silicone molds or a greased baking dish. Allow it to cool at room temperature for 10–15 minutes, then refrigerate for 2–3 hours until firm.
Once set, remove gummies from molds, and store them in an airtight container at room temperature or in the fridge.