Update

src/main/java/systems/brn/televator/Televator.java

@@ -1,7 +1,10 @@
 package systems.brn.televator;
 
 import com.mojang.authlib.GameProfile;
+import eu.pb4.polymer.resourcepack.extras.api.ResourcePackExtras;
+import eu.pb4.polymer.resourcepack.impl.client.rendering.PolymerResourcePack;
 import net.minecraft.server.network.ServerPlayerEntity;
+import net.minecraft.util.Identifier;
 import systems.brn.televator.blocks.TelevatorBlock;
 import eu.pb4.polymer.resourcepack.api.PolymerResourcePackUtils;
 import net.fabricmc.api.ModInitializer;
@@ -18,8 +21,8 @@ public class Televator implements ModInitializer {
 
     @Override
     public void onInitialize() {
-
         PolymerResourcePackUtils.addModAssets(MODID);
+        ResourcePackExtras.forDefault().addBridgedModelsFolder(Identifier.of(MODID, "item"));
         PolymerResourcePackUtils.markAsRequired();
 
         TelevatorBlock.register();

src/main/java/systems/brn/televator/items/TelevatorBlockItem.java

@@ -1,5 +1,9 @@
 package systems.brn.televator.items;
 
+import eu.pb4.polymer.resourcepack.extras.api.ResourcePackExtras;
+import eu.pb4.polymer.resourcepack.extras.api.format.item.model.BasicItemModel;
+import eu.pb4.polymer.resourcepack.impl.client.rendering.PolymerResourcePack;
+import net.minecraft.resource.ResourcePack;
 import systems.brn.televator.Televator;
 import eu.pb4.polymer.core.api.item.PolymerItem;
 import eu.pb4.polymer.resourcepack.api.PolymerResourcePackUtils;
@@ -16,7 +20,7 @@ public class TelevatorBlockItem extends BlockItem implements PolymerItem {
 
     public TelevatorBlockItem(Settings settings, Block block, String modelId) {
         super(block, settings);
-        this.polymerModel = Identifier.of(Televator.MODID, "item/" + modelId);
+        this.polymerModel = Identifier.of(Televator.MODID, modelId);
     }
 
     @Override

src/main/resources/assets/televator/items/televator.json

@@ -0,0 +1,6 @@
+{
+  "model": {
+    "type": "minecraft:model",
+    "model": "televator:item/televator"
+  }
+}