I have created a new desert-pyramid datapack.
With this you can insert your own desert-pyramids into your space worlds.
You should use my updated space resourcepack 1.19.1 for this (optifine is necessary).
The pyramids should appear in the biome: desert
Resourcepack: https://www.curseforge.com/minecraft/texture-packs/norzeteus-space-1-13-128x128-ctm-3d-optifine
Optifine original dwnld: https://optifine.net/downloads