Help with adding multiple textures onto a block

I am creating a very small mod for a modpack that adds military-style lockers. I created a model in blockbench, and imported it into MCreator. There are multiple textures for the model. This is the model so far on BlockBench:

https://imgur.com/a/0kxkdkb

However once it was imported as a block, I loaded it with a result of missing textures. https://imgur.com/a/dEvco3Q

Do I have to combine everything onto one texture? Does MCreator actually have support for custom models mapped to multiple textures and i am just doing it wrong? Or it might just be a case of mapping the wrong textures to the wrong slots.