This is all done using overlays.
Each letter is an overlay. The creator would’ve uploaded each one individually twice - one with the glow effect and one without. They would have the letters with the glow shift in to that position, while the ones without glow would already be there with opacity set to 0. Then you would turn opacity off and back on for the letters with the glow effect, and do the opposite for the ones without the glow to give it that blinking effect.
The glow effect would be done using a photo editing app outside of the episode portal.