Add watermelon rind, tomato paste, vinegar, sugar, Worcestershire, oil and garlic to Instant Pot. Place lid on Instant Pot and set value to Sealing position. Cook on high 10 minutes. Once done cooking, quick release steam and remove lid.
Let cool before transferring to food processor or blender and blend until smooth.
Notes
If you are making this delicious sauce on the stove top you will:
Add all the ingredients to a medium size pot on the stove over medium heat.
Bring to a boil, stirring constantly.
Reduce heat and simmer for about an hour. Your homemade watermelon BBQ sauce will start to thicken.
Remove the sauce from the heat and place into a food processor or blender and puree.
Cool to room temperature, and then refrigerate until ready to use.