After saving my world in Litematica, I can view the Schematic model with Fabric version. However, I can't view it in normal game 1.14.4! I want to play the map without using any mod. Please help!

if you want to see the schematic/litematic, the only way is with litematica.

I assume you mean you want all the blocks to be placed in the world? You can do that in Creative mode by switching to the Paste schematic in world mode and using the executeOperation hotkey. It sounds like you saved a big area(?) so the pasting can then also take a long time due to light updates etc.

Thanks for your help! I will try to paste them in the world. Also, I have 2 big schematics placed. I hope saving them won't crash the game...

EDIT: It almost crashes!!