Either I answer your question or stick to your limitations and not answer at all.
So, let me explain using a small section of your image.
What is a sparkle on a reflective material?
It is a flare of an overexposed zone that is reflecting the full intensity of the light source.
A "flare" is the effect of an intense enough light so some internal reflections or diffractions from the lens are captured.
of an overexposed zone A light source is several magnitudes more intense than a pure matt white material. A flare looks bigger than the zone itself. The light is spilled out.
that is reflecting the full intensity of the light source Meaning that the material is not white, but glossy or metallic, and the incident angle and the reflective angle are right so what you are seeing is a reflection of the light source.
So. I am pretty sure in your house or outdoors you have light sources. Checked.
But does the angle of the reflection points this reflection to your camera lens?
The probability is very low. At most, you will have only 1 or 2 of those little mirrors pointing somewhere near your camera. If you point a strong flashlight on a dark room you will see the room filled with small dots. One or two of those small dots need to point to your tiny smartphone lens.
In order to augment the possibility of capturing the reflection of the light source, you can use a bigger light source. Lot bigger. Aka a softbox.
Normally light sources, indoors and outdoors are point lights. Just one light bulb here and there, and the sun.
Even a small softbox let's say only 60x60cm, near the subject has several hundreds or thousand times more area than a point light. Increasing the possibility of seeing that reflection.
So, either you move a lot trying to capture one random reflection (probably having one assistant giving you instructions if he or she can see the reflection at all), or you get a bigger light source.
You can also try Star Filters, (or Starburst Filters, or Streak Filters) this can produce a flare with less intense light than normally needed for internal reflections.
You can simply smudge your lens and point to a light source to make a quick test.
Or add them in post.