freehand lines neon glow

The 't' above look weird. You can use a text polygon with neon glow in this case. You can edit the control points if you want the irregular look of freehand.

1. ┇
2. Text Outline
3. enter t、size→OK
4. Tap the rectange on the toolbar, the 't' is filled with color.
5. Tap the 't'.  is shown on the bottom-left. Tap it to edit the color and neon glow.

freehand rainbow/star/heart strokes.  The star/heart can be replaced with any emoji symbol.

The outlines of script font have overlappings. The neon glow looks weird.

To generate merged outlines, check 'Script font merge' in the dialog of text outline generation.