Those are screen captures of a tile map, not a tile set.
If you want to export a tile map as an image, then use Export As.
If you want to export a tile map as a set of indices that reference a tile set, then you need to either find or make a Lua script to do so.
2,3,4,5,6,7,8,9,10,11,12,12,
39,40,41,42,43,44,45,46,47,48,12,12,
85,86,87,88,89,90,91,92,93,94,12,12,
122,123,124,125,126,127,128,129,12,12,12,12,
162,163,164,165,12,12,12,166,12,12,12,12
Here are two threads to try:
I have a script to export to Tiled here, but it uses xml format, not json. GDevelop’s docs say it accepts json only.